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  <div class="section" id="lazr-config">
<h1>LAZR config<a class="headerlink" href="#lazr-config" title="Permalink to this headline"></a></h1>
<p>The LAZR config system is typically used to manage process configuration.
Process configuration is for saying how things change when we run systems on
different machines, or under different circumstances.</p>
<p>This system uses ini-like file format of section, keys, and values.  The
config file supports inheritance to minimize duplication of information across
files. The format supports schema validation.</p>
<div class="section" id="configschema">
<h2>ConfigSchema<a class="headerlink" href="#configschema" title="Permalink to this headline"></a></h2>
<p>A schema is loaded by instantiating the ConfigSchema class with the path to a
configuration file. The schema is explicitly derived from the information in
the configuration file.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">pkg_resources</span> <span class="k">import</span> <span class="n">resource_string</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">raw_schema</span> <span class="o">=</span> <span class="n">resource_string</span><span class="p">(</span><span class="s1">&#39;lazr.config.tests.testdata&#39;</span><span class="p">,</span> <span class="s1">&#39;base.conf&#39;</span><span class="p">)</span>
</pre></div>
</div>
<p>The config file contains sections enclosed in square brackets
(e.g. <code class="docutils literal"><span class="pre">[section]</span></code>).  The section name may be divided into major and minor
categories using a dot (<code class="docutils literal"><span class="pre">.</span></code>).  Beneath each section is a list of key-value
pairs, separated by a colon (<code class="docutils literal"><span class="pre">:</span></code>).</p>
<p>Multiple sections with the same major category may have their keys defined in
another section that appends the <code class="docutils literal"><span class="pre">.template</span></code> suffix to the category name.</p>
<p>A section with <code class="docutils literal"><span class="pre">.optional</span></code> suffix is not required.  Lines that start with a
hash (<code class="docutils literal"><span class="pre">#</span></code>) are comments.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">pkg_resources</span> <span class="k">import</span> <span class="n">resource_string</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">raw_schema</span> <span class="o">=</span> <span class="n">resource_string</span><span class="p">(</span><span class="s1">&#39;lazr.config.tests.testdata&#39;</span><span class="p">,</span> <span class="s1">&#39;base.conf&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">raw_schema</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">&#39;utf-8&#39;</span><span class="p">))</span>
<span class="go"># This section defines required keys and default values.</span>
<span class="go">[section_1]</span>
<span class="go">key1: foo</span>
<span class="go">key2: bar and baz</span>
<span class="go">key3: Launchpad&amp;nbsp;rocks</span>
<span class="go">key4: F&amp;#028c;k yeah!</span>
<span class="go">key5:</span>
<span class="go"># This section is required, and it defines all the keys for its category.</span>
<span class="go">[section-2.app-b]</span>
<span class="go">key1: True</span>
<span class="go"># This section is optional; it uses the keys defined</span>
<span class="go"># by section_3.template.</span>
<span class="go">[section_3.app_a.optional]</span>
<span class="go"># This is a required section whose keys are defined by section_3.template</span>
<span class="go"># and it defines a new key.</span>
<span class="go">[section_3.app_b]</span>
<span class="go">key2: changed</span>
<span class="go">key3: unique</span>
<span class="go"># These sections define a common set of required keys and default values.</span>
<span class="go">[section_3.template]</span>
<span class="go">key1: 17</span>
<span class="go">key2: 3.1415</span>
<span class="go"># This section is optional.</span>
<span class="go">[section-5.optional]</span>
<span class="go">key1: something</span>
<span class="go"># This section has a name similar to a category.</span>
<span class="go">[section_33]</span>
<span class="go">key1: fnord</span>
<span class="go">key2: multiline value 1</span>
<span class="go">   multiline value 2</span>
</pre></div>
</div>
<p>To create the schema, provide a file name.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config</span> <span class="k">import</span> <span class="n">ConfigSchema</span>
<span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config.interfaces</span> <span class="k">import</span> <span class="n">IConfigSchema</span>
<span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">pkg_resources</span> <span class="k">import</span> <span class="n">resource_filename</span>
<span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">zope.interface.verify</span> <span class="k">import</span> <span class="n">verifyObject</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">base_conf</span> <span class="o">=</span> <span class="n">resource_filename</span><span class="p">(</span>
<span class="gp">... </span>    <span class="s1">&#39;lazr.config.tests.testdata&#39;</span><span class="p">,</span> <span class="s1">&#39;base.conf&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">schema</span> <span class="o">=</span> <span class="n">ConfigSchema</span><span class="p">(</span><span class="n">base_conf</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">IConfigSchema</span><span class="p">,</span> <span class="n">schema</span><span class="p">)</span>
<span class="go">True</span>
</pre></div>
</div>
<p>The schema has a name and a file name.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">schema</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">base.conf</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="s1">&#39;file:&#39;</span><span class="p">,</span> <span class="n">schema</span><span class="o">.</span><span class="n">filename</span><span class="p">)</span>
<span class="go">file: ...lazr/config/tests/testdata/base.conf</span>
</pre></div>
</div>
<p>If you provide an optional file-like object as a second argument to the
constructor, that is used instead of opening the named file implicitly.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="n">base_conf</span><span class="p">,</span> <span class="s1">&#39;r&#39;</span><span class="p">)</span> <span class="k">as</span> <span class="n">file_object</span><span class="p">:</span>
<span class="gp">... </span>    <span class="n">other_schema</span> <span class="o">=</span> <span class="n">ConfigSchema</span><span class="p">(</span><span class="s1">&#39;/does/not/exist.conf&#39;</span><span class="p">,</span> <span class="n">file_object</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">IConfigSchema</span><span class="p">,</span> <span class="n">other_schema</span><span class="p">)</span>
<span class="go">True</span>
</pre></div>
</div>
<p>For such schemas, the file name is taken from the first argument.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">other_schema</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">exist.conf</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">other_schema</span><span class="o">.</span><span class="n">filename</span><span class="p">)</span>
<span class="go">/does/not/exist.conf</span>
</pre></div>
</div>
<p>A schema is made up of multiple SchemaSections. They can be iterated
over in a loop as needed.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">operator</span> <span class="k">import</span> <span class="n">attrgetter</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">section_schema</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">schema</span><span class="p">,</span> <span class="n">key</span><span class="o">=</span><span class="n">attrgetter</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">)):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">section_schema</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">section-2.app-b</span>
<span class="go">section-5</span>
<span class="go">section_1</span>
<span class="go">section_3.app_a</span>
<span class="go">section_3.app_b</span>
<span class="go">section_33</span>
</pre></div>
</div>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">section_schema</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">other_schema</span><span class="p">,</span> <span class="n">key</span><span class="o">=</span><span class="n">attrgetter</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">)):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">section_schema</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">section-2.app-b</span>
<span class="go">section-5</span>
<span class="go">section_1</span>
<span class="go">section_3.app_a</span>
<span class="go">section_3.app_b</span>
<span class="go">section_33</span>
</pre></div>
</div>
<p>You can check if the schema contains a section name, and that can be
used to access the SchemaSection as a subscript.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;section_1&#39;</span> <span class="ow">in</span> <span class="n">schema</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;section-4&#39;</span> <span class="ow">in</span> <span class="n">schema</span>
<span class="go">False</span>
</pre></div>
</div>
<p>A SectionSchema can be retrieved from the schema using the <code class="docutils literal"><span class="pre">[]</span></code> operator.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">section_schema_1</span> <span class="o">=</span> <span class="n">schema</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">]</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">section_schema_1</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">section_1</span>
</pre></div>
</div>
<p>Processes often require resources like databases or virtual hosts that have a
common category of keys.  The list of all category names can be retrieved via
the categories attribute.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">name</span> <span class="ow">in</span> <span class="n">schema</span><span class="o">.</span><span class="n">category_names</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">name</span><span class="p">)</span>
<span class="go">section-2</span>
<span class="go">section_3</span>
</pre></div>
</div>
<p>The list of SchemaSections that share common category can be retrieved
using <code class="docutils literal"><span class="pre">getByCategory()</span></code>.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">all_section_3</span> <span class="o">=</span> <span class="n">schema</span><span class="o">.</span><span class="n">getByCategory</span><span class="p">(</span><span class="s1">&#39;section_3&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">section_schema</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">all_section_3</span><span class="p">,</span> <span class="n">key</span><span class="o">=</span><span class="n">attrgetter</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">)):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">section_schema</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">section_3.app_a</span>
<span class="go">section_3.app_b</span>
</pre></div>
</div>
<p>You can pass a default argument to <code class="docutils literal"><span class="pre">getByCategory()</span></code> to avoid the exception.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">missing</span> <span class="o">=</span> <span class="nb">object</span><span class="p">()</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">schema</span><span class="o">.</span><span class="n">getByCategory</span><span class="p">(</span><span class="s1">&#39;non-section&#39;</span><span class="p">,</span> <span class="n">missing</span><span class="p">)</span> <span class="ow">is</span> <span class="n">missing</span>
<span class="go">True</span>
</pre></div>
</div>
</div>
<div class="section" id="schemasection">
<h2>SchemaSection<a class="headerlink" href="#schemasection" title="Permalink to this headline"></a></h2>
<p>A SchemaSection behaves similar to a dictionary.  It has keys and values.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config.interfaces</span> <span class="k">import</span> <span class="n">ISectionSchema</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">section_schema_1</span> <span class="o">=</span> <span class="n">schema</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">]</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">ISectionSchema</span><span class="p">,</span> <span class="n">section_schema_1</span><span class="p">)</span>
<span class="go">True</span>
</pre></div>
</div>
<p>Each SchemaSection has a name.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">section_schema_1</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">section_1</span>
</pre></div>
</div>
<p>A SchemaSection can return a 2-tuple of its category name and specific name
parts.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">name</span> <span class="ow">in</span> <span class="n">schema</span><span class="p">[</span><span class="s1">&#39;section_3.app_b&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">category_and_section_names</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">name</span><span class="p">)</span>
<span class="go">section_3</span>
<span class="go">app_b</span>
</pre></div>
</div>
<p>The category name will be <code class="docutils literal"><span class="pre">None</span></code> if the SchemaSection&#8217;s name does not
contain a category.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">name</span> <span class="ow">in</span> <span class="n">section_schema_1</span><span class="o">.</span><span class="n">category_and_section_names</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">name</span><span class="p">)</span>
<span class="go">None</span>
<span class="go">section_1</span>
</pre></div>
</div>
<p>Optional sections have the optional attribute set to <code class="docutils literal"><span class="pre">True</span></code>:</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">section_schema_1</span><span class="o">.</span><span class="n">optional</span>
<span class="go">False</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">schema</span><span class="p">[</span><span class="s1">&#39;section_3.app_a&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">optional</span>
<span class="go">True</span>
</pre></div>
</div>
<p>A key can be verified to be in a section.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;key1&#39;</span> <span class="ow">in</span> <span class="n">section_schema_1</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;nonkey&#39;</span> <span class="ow">in</span> <span class="n">section_schema_1</span>
<span class="go">False</span>
</pre></div>
</div>
<p>A key can be accessed directly using as a subscript of the SchemaSection.  The
value is always a string.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">section_schema_1</span><span class="p">[</span><span class="s1">&#39;key3&#39;</span><span class="p">])</span>
<span class="go">Launchpad&amp;nbsp;rocks</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">section_schema_1</span><span class="p">[</span><span class="s1">&#39;key5&#39;</span><span class="p">]</span>
<span class="go">&#39;&#39;</span>
</pre></div>
</div>
<p>An error is raised if a non-existent key is accessed.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">section_schema_1</span><span class="p">[</span><span class="s1">&#39;not-exist&#39;</span><span class="p">]</span>
<span class="gt">Traceback (most recent call last):</span>
  <span class="c">...</span>
<span class="gr">KeyError</span>: <span class="n">...</span>
</pre></div>
</div>
<p>In the conf file, <code class="docutils literal"><span class="pre">[section_1]</span></code> is a default section that defines keys and
values.  The values specified in the section schema will be used as default
values if not overridden in the configuration.  In the case of <em>key5</em>, the key
had no explicit value, so the value is an empty string.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">key</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">section_schema_1</span><span class="p">):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="s1">&#39;:&#39;</span><span class="p">,</span> <span class="n">section_schema_1</span><span class="p">[</span><span class="n">key</span><span class="p">])</span>
<span class="go">key1 : foo</span>
<span class="go">key2 : bar and baz</span>
<span class="go">key3 : Launchpad&amp;nbsp;rocks</span>
<span class="go">key4 : F&amp;#028c;k yeah!</span>
<span class="go">key5 :</span>
</pre></div>
</div>
<p>In the conf file <code class="docutils literal"><span class="pre">[section_3.template]</span></code> defines a common set of keys and
default values for <code class="docutils literal"><span class="pre">[section_3.app_a]</span></code> and <code class="docutils literal"><span class="pre">[section_3.app_b]</span></code>.  When a
section defines different keys and default values from the template, the new
data overlays the template data.  This is the case for section
<code class="docutils literal"><span class="pre">[section_3.app_b]</span></code>.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">section_schema</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">all_section_3</span><span class="p">,</span> <span class="n">key</span><span class="o">=</span><span class="n">attrgetter</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">)):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">section_schema</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="gp">... </span>    <span class="k">for</span> <span class="n">key</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">section_schema</span><span class="p">):</span>
<span class="gp">... </span>        <span class="nb">print</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="s1">&#39;:&#39;</span><span class="p">,</span> <span class="n">section_schema</span><span class="p">[</span><span class="n">key</span><span class="p">])</span>
<span class="go">section_3.app_a</span>
<span class="go">key1 : 17</span>
<span class="go">key2 : 3.1415</span>
<span class="go">section_3.app_b</span>
<span class="go">key1 : 17</span>
<span class="go">key2 : changed</span>
<span class="go">key3 : unique</span>
</pre></div>
</div>
</div>
<div class="section" id="configschema-validation">
<h2>ConfigSchema validation<a class="headerlink" href="#configschema-validation" title="Permalink to this headline"></a></h2>
<p>The schema parser is self-validating.  It checks that the character encoding
is ASCII, and that the data is not ambiguous or self-contradicting.  Keys must
exist inside sections and section names may not be defined twice.  Sections
may belong to only one category, and only letters, numbers, dots and dashes
may be present in section names.</p>
</div>
<div class="section" id="iconfigloader">
<h2>IConfigLoader<a class="headerlink" href="#iconfigloader" title="Permalink to this headline"></a></h2>
<p>ConfigSchema implements the two methods in the IConfigLoader interface.  A
Config is created by a schema using either the <code class="docutils literal"><span class="pre">load()</span></code> or <code class="docutils literal"><span class="pre">loadFile()</span></code>
methods to return a Config instance.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config.interfaces</span> <span class="k">import</span> <span class="n">IConfigLoader</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">IConfigLoader</span><span class="p">,</span> <span class="n">schema</span><span class="p">)</span>
<span class="go">True</span>
</pre></div>
</div>
<p>The <code class="docutils literal"><span class="pre">load()</span></code> method accepts a filename.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">local_conf</span> <span class="o">=</span> <span class="n">resource_filename</span><span class="p">(</span>
<span class="gp">... </span>    <span class="s1">&#39;lazr.config.tests.testdata&#39;</span><span class="p">,</span> <span class="s1">&#39;local.conf&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span> <span class="o">=</span> <span class="n">schema</span><span class="o">.</span><span class="n">load</span><span class="p">(</span><span class="n">local_conf</span><span class="p">)</span>
</pre></div>
</div>
<p>The <code class="docutils literal"><span class="pre">loadFile()</span></code> method accepts a file-like object and an optional filename
keyword argument.  The filename argument must be passed if the file-like
object does not have a <code class="docutils literal"><span class="pre">name</span></code> attribute.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">try</span><span class="p">:</span>
<span class="gp">... </span>    <span class="kn">from</span> <span class="nn">io</span> <span class="k">import</span> <span class="n">StringIO</span>
<span class="gp">... </span><span class="k">except</span> <span class="ne">ImportError</span><span class="p">:</span>
<span class="gp">... </span>    <span class="c1"># Python 2</span>
<span class="gp">... </span>    <span class="kn">from</span> <span class="nn">StringIO</span> <span class="k">import</span> <span class="n">StringIO</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">bad_data</span> <span class="o">=</span> <span class="p">(</span><span class="s2">&quot;&quot;&quot;</span>
<span class="gp">... </span><span class="s2">    [meta]</span>
<span class="gp">... </span><span class="s2">    metakey: unsupported</span>
<span class="gp">... </span><span class="s2">    [unknown-section]</span>
<span class="gp">... </span><span class="s2">    key1 = value1</span>
<span class="gp">... </span><span class="s2">    [section_1]</span>
<span class="gp">... </span><span class="s2">    keyn: unknown key</span>
<span class="gp">... </span><span class="s2">    key1: bad character in caf</span><span class="se">\xc3</span><span class="s2">)</span>
<span class="gp">... </span><span class="s2">    [section_3.template]</span>
<span class="gp">... </span><span class="s2">    key1: schema suffixes are not permitted&quot;&quot;&quot;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">bad_config</span> <span class="o">=</span> <span class="n">schema</span><span class="o">.</span><span class="n">loadFile</span><span class="p">(</span>
<span class="gp">... </span>    <span class="n">StringIO</span><span class="p">(</span><span class="n">bad_data</span><span class="p">),</span> <span class="s1">&#39;bad conf&#39;</span><span class="p">)</span>
</pre></div>
</div>
</div>
<div class="section" id="config">
<h2>Config<a class="headerlink" href="#config" title="Permalink to this headline"></a></h2>
<p>The config represents the local configuration of the process on a system.  It
is validated with a schema.  It extends the schema, or other conf files, to
define the specific differences from the extended files that are required to
run the local processes.</p>
<p>The object returned by <code class="docutils literal"><span class="pre">load()</span></code> provides both the <code class="docutils literal"><span class="pre">IConfigData</span></code> and
<code class="docutils literal"><span class="pre">IStackableConfig</span></code> interfaces.  <code class="docutils literal"><span class="pre">IConfigData</span></code> is for read-only access to
the configuration data.  A process configuration is made up of a stack of
different <code class="docutils literal"><span class="pre">IConfigData</span></code>.  The <code class="docutils literal"><span class="pre">IStackableConfig</span></code> interface provides the
methods used to manipulate that stack of configuration overlays.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config.interfaces</span> <span class="k">import</span> <span class="n">IConfigData</span><span class="p">,</span> <span class="n">IStackableConfig</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">IConfigData</span><span class="p">,</span> <span class="n">config</span><span class="p">)</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">IStackableConfig</span><span class="p">,</span> <span class="n">config</span><span class="p">)</span>
<span class="go">True</span>
</pre></div>
</div>
<p>Like the schema file, the conf file is made up of sections with keys.  The
sections may belong to a category.  Unlike the schema file, it does not have
template or optional sections.  The <code class="docutils literal"><span class="pre">[meta]</span></code> section has the extends key
that declares that this conf extends <code class="docutils literal"><span class="pre">shared.conf</span></code>.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="n">local_conf</span><span class="p">,</span> <span class="s1">&#39;rt&#39;</span><span class="p">)</span> <span class="k">as</span> <span class="n">local_file</span><span class="p">:</span>
<span class="gp">... </span>    <span class="n">raw_conf</span> <span class="o">=</span> <span class="n">local_file</span><span class="o">.</span><span class="n">read</span><span class="p">()</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">raw_conf</span><span class="p">)</span>
<span class="go">[meta]</span>
<span class="go">extends: shared.conf</span>
<span class="go"># Localize a key for section_1.</span>
<span class="go">[section_1]</span>
<span class="go">key5: local value</span>
<span class="go"># Accept the default values for the optional section-5.</span>
<span class="go">[section-5]</span>
</pre></div>
</div>
<p>The <code class="docutils literal"><span class="pre">.master</span></code> section allows admins to define configurations for an
arbitrary number of processes.  If the schema defines <code class="docutils literal"><span class="pre">.master</span></code> sections,
then the conf file can contain sections that extend the <code class="docutils literal"><span class="pre">.master</span></code> section.
These are like categories with templates except that the section names
extending <code class="docutils literal"><span class="pre">.master</span></code> need not be named in the schema file.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">master_schema_conf</span> <span class="o">=</span> <span class="n">resource_filename</span><span class="p">(</span>
<span class="gp">... </span>    <span class="s1">&#39;lazr.config.tests.testdata&#39;</span><span class="p">,</span> <span class="s1">&#39;master.conf&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">master_local_conf</span> <span class="o">=</span> <span class="n">resource_filename</span><span class="p">(</span>
<span class="gp">... </span>    <span class="s1">&#39;lazr.config.tests.testdata&#39;</span><span class="p">,</span> <span class="s1">&#39;master-local.conf&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">master_schema</span> <span class="o">=</span> <span class="n">ConfigSchema</span><span class="p">(</span><span class="n">master_schema_conf</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">sections</span> <span class="o">=</span> <span class="n">master_schema</span><span class="o">.</span><span class="n">getByCategory</span><span class="p">(</span><span class="s1">&#39;thing&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">name</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">section</span><span class="o">.</span><span class="n">name</span> <span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="n">sections</span><span class="p">):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">name</span><span class="p">)</span>
<span class="go">thing.master</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">master_conf</span> <span class="o">=</span> <span class="n">master_schema</span><span class="o">.</span><span class="n">load</span><span class="p">(</span><span class="n">master_local_conf</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">sections</span> <span class="o">=</span> <span class="n">master_conf</span><span class="o">.</span><span class="n">getByCategory</span><span class="p">(</span><span class="s1">&#39;thing&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">name</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">section</span><span class="o">.</span><span class="n">name</span> <span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="n">sections</span><span class="p">):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">name</span><span class="p">)</span>
<span class="go">thing.one</span>
<span class="go">thing.two</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">name</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">section</span><span class="o">.</span><span class="n">foo</span> <span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="n">sections</span><span class="p">):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">name</span><span class="p">)</span>
<span class="go">1</span>
<span class="go">2</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">master_conf</span><span class="o">.</span><span class="n">thing</span><span class="o">.</span><span class="n">one</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">thing.one</span>
</pre></div>
</div>
<p>The <code class="docutils literal"><span class="pre">shared.conf</span></code> file derives the keys and default values from the schema.
This config was loaded before <code class="docutils literal"><span class="pre">local.conf</span></code> because its sections and values
are required to be in place before <code class="docutils literal"><span class="pre">local.conf</span></code> applies its changes.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">shared_config</span> <span class="o">=</span> <span class="n">resource_filename</span><span class="p">(</span>
<span class="gp">... </span>    <span class="s1">&#39;lazr.config.tests.testdata&#39;</span><span class="p">,</span> <span class="s1">&#39;shared.conf&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="n">shared_config</span><span class="p">,</span> <span class="s1">&#39;rt&#39;</span><span class="p">)</span> <span class="k">as</span> <span class="n">shared_file</span><span class="p">:</span>
<span class="gp">... </span>    <span class="n">raw_conf</span> <span class="o">=</span> <span class="n">shared_file</span><span class="o">.</span><span class="n">read</span><span class="p">()</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">raw_conf</span><span class="p">)</span>
<span class="go"># The schema is defined by base.conf.</span>
<span class="go"># Localize a key for section_1.</span>
<span class="go">[section_1]</span>
<span class="go">key2: sharing is fun</span>
<span class="go">key5: shared value</span>
</pre></div>
</div>
<p>The config that was loaded has <code class="docutils literal"><span class="pre">name</span></code> and <code class="docutils literal"><span class="pre">filename</span></code> attributes to
identify the configuration.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">config</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">local.conf</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="s1">&#39;file:&#39;</span><span class="p">,</span> <span class="n">config</span><span class="o">.</span><span class="n">filename</span><span class="p">)</span>
<span class="go">file: ...lazr/config/tests/testdata/local.conf</span>
</pre></div>
</div>
<p>The config can access the schema via the schema property.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">config</span><span class="o">.</span><span class="n">schema</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">base.conf</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">schema</span> <span class="ow">is</span> <span class="n">schema</span>
<span class="go">True</span>
</pre></div>
</div>
<p>A config is made up of multiple Sections like the schema.  They can be
iterated over in a loop as needed.  This config inherited several sections
defined in schema.  Note that the meta section is not present because it
pertains to the config system, not to the processes being configured.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">config</span><span class="p">,</span> <span class="n">key</span><span class="o">=</span><span class="n">attrgetter</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">)):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">section</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">section-2.app-b</span>
<span class="go">section-5</span>
<span class="go">section_1</span>
<span class="go">section_3.app_b</span>
<span class="go">section_33</span>
</pre></div>
</div>
<p>You can check if a section name is in a config.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;section_1&#39;</span> <span class="ow">in</span> <span class="n">config</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;bad-section&#39;</span> <span class="ow">in</span> <span class="n">config</span>
<span class="go">False</span>
</pre></div>
</div>
<p>Optional SchemaSections are not inherited by the config.  A config file must
declare all optional sections.  Including the section heading is enough to
inherit the section and its keys.  The config file may localize the keys by
declaring them too.  The <code class="docutils literal"><span class="pre">local.conf</span></code> file includes <code class="docutils literal"><span class="pre">section-5</span></code>, but not
<code class="docutils literal"><span class="pre">section_3.app_a</span></code>.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;section_3.app_a&#39;</span> <span class="ow">in</span> <span class="n">config</span>
<span class="go">False</span>
<span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;section_3.app_a&#39;</span> <span class="ow">in</span> <span class="n">config</span><span class="o">.</span><span class="n">schema</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">schema</span><span class="p">[</span><span class="s1">&#39;section_3.app_a&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">optional</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;section-5&#39;</span> <span class="ow">in</span> <span class="n">config</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;section-5&#39;</span> <span class="ow">in</span> <span class="n">config</span><span class="o">.</span><span class="n">schema</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">schema</span><span class="p">[</span><span class="s1">&#39;section-5&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">optional</span>
<span class="go">True</span>
</pre></div>
</div>
<p>A Section can be accessed using subscript notation.  Accessing a section that
does not exist will raise a NoSectionError.  NoSectionError is raised for a
undeclared optional sections too.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">section_1</span> <span class="o">=</span> <span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">]</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">section_1</span><span class="o">.</span><span class="n">name</span> <span class="ow">in</span> <span class="n">config</span>
<span class="go">True</span>
</pre></div>
</div>
<p>Config supports category access like Schema does.  The list of categories are
returned by the <code class="docutils literal"><span class="pre">category_names</span></code> property.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">name</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">config</span><span class="o">.</span><span class="n">category_names</span><span class="p">):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">name</span><span class="p">)</span>
<span class="go">section-2</span>
<span class="go">section_3</span>
</pre></div>
</div>
<p>All the sections that belong to a category can be retrieved using the
<code class="docutils literal"><span class="pre">getByCategory()</span></code> method.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="n">config</span><span class="o">.</span><span class="n">getByCategory</span><span class="p">(</span><span class="s1">&#39;section_3&#39;</span><span class="p">):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">section_schema</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">section_3.app_b</span>
</pre></div>
</div>
<p>Passing a non-existent category_name to the method will raise a
NoCategoryError.  As with schemas, you can pass a default argument to
<code class="docutils literal"><span class="pre">getByCategory()</span></code> to avoid the exception.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">missing</span> <span class="o">=</span> <span class="nb">object</span><span class="p">()</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">getByCategory</span><span class="p">(</span><span class="s1">&#39;non-section&#39;</span><span class="p">,</span> <span class="n">missing</span><span class="p">)</span> <span class="ow">is</span> <span class="n">missing</span>
<span class="go">True</span>
</pre></div>
</div>
</div>
<div class="section" id="section">
<h2>Section<a class="headerlink" href="#section" title="Permalink to this headline"></a></h2>
<p>A Section behaves similar to a dictionary.  It has keys and values.  It
supports some specialize access methods and properties for working with the
values.  Each Section has a name.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config.interfaces</span> <span class="k">import</span> <span class="n">ISection</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">ISection</span><span class="p">,</span> <span class="n">section_1</span><span class="p">)</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">section_1</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">section_1</span>
</pre></div>
</div>
<p>Like SectionSchemas, sections can return a 2-tuple of their category name and
specific name parts.  The category name will be <code class="docutils literal"><span class="pre">None</span></code> if the section&#8217;s name
does not contain a category.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">name</span> <span class="ow">in</span> <span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_3.app_b&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">category_and_section_names</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">name</span><span class="p">)</span>
<span class="go">section_3</span>
<span class="go">app_b</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">name</span> <span class="ow">in</span> <span class="n">section_1</span><span class="o">.</span><span class="n">category_and_section_names</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">name</span><span class="p">)</span>
<span class="go">None</span>
<span class="go">section_1</span>
</pre></div>
</div>
<p>The Section&#8217;s type is the same type as the <code class="docutils literal"><span class="pre">ConfigSchema.section_factory</span></code>.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">section_1</span>
<span class="go">&lt;lazr.config...Section object at ...&gt;</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">schema</span><span class="o">.</span><span class="n">section_factory</span>
<span class="go">&lt;class &#39;lazr.config...Section&#39;&gt;</span>
</pre></div>
</div>
<p>A key can be verified to be in a Section.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;key1&#39;</span> <span class="ow">in</span> <span class="n">section_1</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;nonkey&#39;</span> <span class="ow">in</span> <span class="n">section_1</span>
<span class="go">False</span>
</pre></div>
</div>
<p>A key can be accessed directly using as a subscript of the Section.
The value is always a string.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">section_1</span><span class="p">[</span><span class="s1">&#39;key3&#39;</span><span class="p">])</span>
<span class="go">Launchpad&amp;nbsp;rocks</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">section_1</span><span class="p">[</span><span class="s1">&#39;key5&#39;</span><span class="p">])</span>
<span class="go">local value</span>
</pre></div>
</div>
<p>An error is raised if a non-existent key is accessed via a subscript.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">section_1</span><span class="p">[</span><span class="s1">&#39;not-exist&#39;</span><span class="p">]</span>
<span class="gt">Traceback (most recent call last):</span>
  <span class="c">...</span>
<span class="gr">KeyError</span>: <span class="n">...</span>
</pre></div>
</div>
<p>The Section keys can be iterated over.  The section has all the keys from the
SectionSchema.  The values came form the schema&#8217;s default values, then the
values from <code class="docutils literal"><span class="pre">shared.conf</span></code> were applied, and lastly, the values from
<code class="docutils literal"><span class="pre">local.conf</span></code> were applied.  The schema provided the values of <code class="docutils literal"><span class="pre">key1</span></code>,
<code class="docutils literal"><span class="pre">key3</span></code>, and <code class="docutils literal"><span class="pre">key4</span></code>. <code class="docutils literal"><span class="pre">shared.conf</span></code> provided the value of <code class="docutils literal"><span class="pre">key2</span></code>
. <code class="docutils literal"><span class="pre">local.conf</span></code> provided <code class="docutils literal"><span class="pre">key5</span></code>.  While <code class="docutils literal"><span class="pre">shared.conf</span></code> provided a
<code class="docutils literal"><span class="pre">key5</span></code>, <code class="docutils literal"><span class="pre">local.conf</span></code> takes precedence.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">key</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">section_1</span><span class="p">):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="s1">&#39;:&#39;</span><span class="p">,</span> <span class="n">section_1</span><span class="p">[</span><span class="n">key</span><span class="p">])</span>
<span class="go">key1 : foo</span>
<span class="go">key2 : sharing is fun</span>
<span class="go">key3 : Launchpad&amp;nbsp;rocks</span>
<span class="go">key4 : F&amp;#028c;k yeah!</span>
<span class="go">key5 : local value</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">section_1</span><span class="o">.</span><span class="n">schema</span><span class="p">[</span><span class="s1">&#39;key5&#39;</span><span class="p">]</span>
<span class="go">&#39;&#39;</span>
</pre></div>
</div>
<p>The schema provided mandatory sections and default values to the config.  So
while the config file did not declare all the sections, they are present.  In
the case of <code class="docutils literal"><span class="pre">section_3.app_b</span></code>, its keys were defined in a template section.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">key</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_3.app_b&#39;</span><span class="p">]):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="s1">&#39;:&#39;</span><span class="p">,</span> <span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_3.app_b&#39;</span><span class="p">][</span><span class="n">key</span><span class="p">])</span>
<span class="go">key1 : 17</span>
<span class="go">key2 : changed</span>
<span class="go">key3 : unique</span>
</pre></div>
</div>
<p>Sections attributes cannot be directly set to shadow config options.  An
<code class="docutils literal"><span class="pre">AttributeError</span></code> is raised when an attempt is made to mutate the config.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_3.app_b&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">key1</span> <span class="o">=</span> <span class="s1">&#39;fail&#39;</span>
<span class="gt">Traceback (most recent call last):</span>
 <span class="c">...</span>
<span class="gr">AttributeError</span>: <span class="n">Config options cannot be set directly.</span>
</pre></div>
</div>
<p>Nor can new attributes be added to a section.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_3.app_b&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">no_such_attribute</span> <span class="o">=</span> <span class="s1">&#39;fail&#39;</span>
<span class="gt">Traceback (most recent call last):</span>
 <span class="c">...</span>
<span class="gr">AttributeError</span>: <span class="n">Config options cannot be set directly.</span>
</pre></div>
</div>
</div>
<div class="section" id="validating-configs">
<h2>Validating configs<a class="headerlink" href="#validating-configs" title="Permalink to this headline"></a></h2>
<p>Config provides the <code class="docutils literal"><span class="pre">validate()</span></code> method to verify that the config is valid
according to the schema.  The method returns <code class="docutils literal"><span class="pre">True</span></code> if the config is valid.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">validate</span><span class="p">()</span>
<span class="go">True</span>
</pre></div>
</div>
<p>When the config is not valid, a ConfigErrors is raised.  The exception has an
<code class="docutils literal"><span class="pre">errors</span></code> property that contains a list of all the errors in the config.</p>
</div>
<div class="section" id="config-overlays">
<h2>Config overlays<a class="headerlink" href="#config-overlays" title="Permalink to this headline"></a></h2>
<p>A conf file may contain a meta section that is used by the config system.  The
config data can access the config it extended using the <code class="docutils literal"><span class="pre">extends</span></code> property.
The object is just the config data; it does not have any config methods.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">config</span><span class="o">.</span><span class="n">extends</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">shared.conf</span>
</pre></div>
</div>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">IConfigData</span><span class="p">,</span> <span class="n">config</span><span class="o">.</span><span class="n">extends</span><span class="p">)</span>
<span class="go">True</span>
</pre></div>
</div>
<p>As Config supports inheritance through the <code class="docutils literal"><span class="pre">extends</span></code> key, each conf file
produces instance of ConfigData, called an <em>overlay</em>.  ConfigData represents
the state of a config.  The <code class="docutils literal"><span class="pre">overlays</span></code> property is a stack of ConfigData as
it was constructed from the schema&#8217;s config to the last config file that was
loaded.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">config_data</span> <span class="ow">in</span> <span class="n">config</span><span class="o">.</span><span class="n">overlays</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">config_data</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">local.conf</span>
<span class="go">shared.conf</span>
<span class="go">base.conf</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">IConfigData</span><span class="p">,</span> <span class="n">config</span><span class="o">.</span><span class="n">overlays</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">])</span>
<span class="go">True</span>
</pre></div>
</div>
<p>Conf files can use the <code class="docutils literal"><span class="pre">extends</span></code> key to specify that it extends a schema
without incurring a processing penalty by loading the schema twice in a row.
The schema can never be the second item in the overlays stack.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">single_config</span> <span class="o">=</span> <span class="n">schema</span><span class="o">.</span><span class="n">load</span><span class="p">(</span><span class="n">schema</span><span class="o">.</span><span class="n">filename</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">config_data</span> <span class="ow">in</span> <span class="n">single_config</span><span class="o">.</span><span class="n">overlays</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">config_data</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">base.conf</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">single_config</span><span class="o">.</span><span class="n">push</span><span class="p">(</span><span class="n">schema</span><span class="o">.</span><span class="n">filename</span><span class="p">,</span> <span class="n">raw_schema</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">&#39;utf-8&#39;</span><span class="p">))</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">config_data</span> <span class="ow">in</span> <span class="n">single_config</span><span class="o">.</span><span class="n">overlays</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">config_data</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">base.conf</span>
</pre></div>
</div>
</div>
<div class="section" id="push">
<h2>push()<a class="headerlink" href="#push" title="Permalink to this headline"></a></h2>
<p>Raw config data can be merged with the config to create a new overlay for
testing.  The <code class="docutils literal"><span class="pre">push()</span></code> method accepts a string of config data.  The data
must conform to the schema.  The <code class="docutils literal"><span class="pre">section_1</span></code> sections&#8217;s keys are updated
when the unparsed data is pushed onto the config.  Note that indented,
unparsed data is passed to <code class="docutils literal"><span class="pre">push()</span></code> in this example; <code class="docutils literal"><span class="pre">push()</span></code> does not
require tests to dedent the test data.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">key</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">]):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="s1">&#39;:&#39;</span><span class="p">,</span> <span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">][</span><span class="n">key</span><span class="p">])</span>
<span class="go">key1 : foo</span>
<span class="go">key2 : sharing is fun</span>
<span class="go">key3 : Launchpad&amp;nbsp;rocks</span>
<span class="go">key4 : F&amp;#028c;k yeah!</span>
<span class="go">key5 : local value</span>

<span class="gp">&gt;&gt;&gt; </span><span class="n">test_data</span> <span class="o">=</span> <span class="p">(</span><span class="s2">&quot;&quot;&quot;</span>
<span class="gp">... </span><span class="s2">    [section_1]</span>
<span class="gp">... </span><span class="s2">    key1: test1</span>
<span class="gp">... </span><span class="s2">    key5:&quot;&quot;&quot;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">push</span><span class="p">(</span><span class="s1">&#39;test config&#39;</span><span class="p">,</span> <span class="n">test_data</span><span class="p">)</span>

<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">key</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">]):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="s1">&#39;:&#39;</span><span class="p">,</span> <span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">][</span><span class="n">key</span><span class="p">])</span>
<span class="go">key1 : test1</span>
<span class="go">key2 : sharing is fun</span>
<span class="go">key3 : Launchpad&amp;nbsp;rocks</span>
<span class="go">key4 : F&amp;#028c;k yeah!</span>
<span class="go">key5 :</span>
</pre></div>
</div>
<p>Besides updating section keys, optional sections can be enabled too.  The
<code class="docutils literal"><span class="pre">section_3.app_a</span></code> section is enabled with the default keys from the schema
in this example.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">schema</span><span class="p">[</span><span class="s1">&#39;section_3.app_a&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">optional</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;section_3.app_a&#39;</span> <span class="ow">in</span> <span class="n">config</span>
<span class="go">False</span>

<span class="gp">&gt;&gt;&gt; </span><span class="n">app_a_data</span> <span class="o">=</span> <span class="s2">&quot;[section_3.app_a]&quot;</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">push</span><span class="p">(</span><span class="s1">&#39;test app_a&#39;</span><span class="p">,</span> <span class="n">app_a_data</span><span class="p">)</span>

<span class="gp">&gt;&gt;&gt; </span><span class="s1">&#39;section_3.app_a&#39;</span> <span class="ow">in</span> <span class="n">config</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">key</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_3.app_a&#39;</span><span class="p">]):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="s1">&#39;:&#39;</span><span class="p">,</span> <span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_3.app_a&#39;</span><span class="p">][</span><span class="n">key</span><span class="p">])</span>
<span class="go">key1 : 17</span>
<span class="go">key2 : 3.1415</span>

<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">key</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">config</span><span class="o">.</span><span class="n">schema</span><span class="p">[</span><span class="s1">&#39;section_3.app_a&#39;</span><span class="p">]):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="s1">&#39;:&#39;</span><span class="p">,</span> <span class="n">config</span><span class="o">.</span><span class="n">schema</span><span class="p">[</span><span class="s1">&#39;section_3.app_a&#39;</span><span class="p">][</span><span class="n">key</span><span class="p">])</span>
<span class="go">key1 : 17</span>
<span class="go">key2 : 3.1415</span>
</pre></div>
</div>
<p>The config&#8217;s name and overlays are updated by <code class="docutils literal"><span class="pre">push()</span></code>.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">config</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">test app_a</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">config</span><span class="o">.</span><span class="n">filename</span><span class="p">)</span>
<span class="go">test app_a</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">config_data</span> <span class="ow">in</span> <span class="n">config</span><span class="o">.</span><span class="n">overlays</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">config_data</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">test app_a</span>
<span class="go">test config</span>
<span class="go">local.conf</span>
<span class="go">shared.conf</span>
<span class="go">base.conf</span>
</pre></div>
</div>
<p>The <code class="docutils literal"><span class="pre">test</span> <span class="pre">app_a</span></code> config did not declare an <code class="docutils literal"><span class="pre">extends</span></code> key in a <code class="docutils literal"><span class="pre">meta</span></code>
section.  Its <code class="docutils literal"><span class="pre">extends</span></code> property is <code class="docutils literal"><span class="pre">None</span></code>, even though it implicitly
extends <code class="docutils literal"><span class="pre">test</span> <span class="pre">config</span></code>.  The <code class="docutils literal"><span class="pre">extends</span></code> property only provides access to
configs that are explicitly extended.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">config</span><span class="o">.</span><span class="n">extends</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">test config</span>
</pre></div>
</div>
<p>The config&#8217;s sections are updated with <code class="docutils literal"><span class="pre">section_3.app_a</span></code> too.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">config</span><span class="p">,</span> <span class="n">key</span><span class="o">=</span><span class="n">attrgetter</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">)):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">section</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">section-2.app-b</span>
<span class="go">section-5</span>
<span class="go">section_1</span>
<span class="go">section_3.app_a</span>
<span class="go">section_3.app_b</span>
<span class="go">section_33</span>
</pre></div>
</div>
<p>A config file may state that it extends its schema (to clearly connect the
config to the schema).  The schema can also be pushed to reset the values in
the config to the schema&#8217;s default values.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">extender_conf_name</span> <span class="o">=</span> <span class="n">resource_filename</span><span class="p">(</span>
<span class="gp">... </span>    <span class="s1">&#39;lazr.config.tests.testdata&#39;</span><span class="p">,</span> <span class="s1">&#39;extender.conf&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">extender_conf_data</span> <span class="o">=</span> <span class="p">(</span><span class="s2">&quot;&quot;&quot;</span>
<span class="gp">... </span><span class="s2">    [meta]</span>
<span class="gp">... </span><span class="s2">    extends: base.conf&quot;&quot;&quot;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">push</span><span class="p">(</span><span class="n">extender_conf_name</span><span class="p">,</span> <span class="n">extender_conf_data</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">config_data</span> <span class="ow">in</span> <span class="n">config</span><span class="o">.</span><span class="n">overlays</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">config_data</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">extender.conf</span>
<span class="go">base.conf</span>
<span class="go">test app_a</span>
<span class="go">test config</span>
<span class="go">local.conf</span>
<span class="go">shared.conf</span>
<span class="go">base.conf</span>
</pre></div>
</div>
<p>The <code class="docutils literal"><span class="pre">section_1</span></code> section was restored to the schema&#8217;s default values.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">key</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">]):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="s1">&#39;:&#39;</span><span class="p">,</span> <span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">][</span><span class="n">key</span><span class="p">])</span>
<span class="go">key1 : foo</span>
<span class="go">key2 : bar and baz</span>
<span class="go">key3 : Launchpad&amp;nbsp;rocks</span>
<span class="go">key4 : F&amp;#028c;k yeah!</span>
<span class="go">key5 :</span>
</pre></div>
</div>
<p><code class="docutils literal"><span class="pre">push()</span></code> can also be used to extend master sections.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">sections</span> <span class="o">=</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">master_conf</span><span class="o">.</span><span class="n">getByCategory</span><span class="p">(</span><span class="s1">&#39;bar&#39;</span><span class="p">),</span>
<span class="gp">... </span>                  <span class="n">key</span><span class="o">=</span><span class="n">attrgetter</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">))</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="n">sections</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">section</span><span class="o">.</span><span class="n">name</span><span class="p">,</span> <span class="n">section</span><span class="o">.</span><span class="n">baz</span><span class="p">)</span>
<span class="go">bar.master badger</span>
<span class="go">bar.soup cougar</span>

<span class="gp">&gt;&gt;&gt; </span><span class="n">master_conf</span><span class="o">.</span><span class="n">push</span><span class="p">(</span><span class="s1">&#39;override&#39;</span><span class="p">,</span> <span class="s2">&quot;&quot;&quot;</span>
<span class="gp">... </span><span class="s2">[bar.two]</span>
<span class="gp">... </span><span class="s2">baz: dolphin</span>
<span class="gp">... </span><span class="s2">&quot;&quot;&quot;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">sections</span> <span class="o">=</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">master_conf</span><span class="o">.</span><span class="n">getByCategory</span><span class="p">(</span><span class="s1">&#39;bar&#39;</span><span class="p">),</span>
<span class="gp">... </span>                  <span class="n">key</span><span class="o">=</span><span class="n">attrgetter</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">))</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="n">sections</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">section</span><span class="o">.</span><span class="n">name</span><span class="p">,</span> <span class="n">section</span><span class="o">.</span><span class="n">baz</span><span class="p">)</span>
<span class="go">bar.soup cougar</span>
<span class="go">bar.two dolphin</span>

<span class="gp">&gt;&gt;&gt; </span><span class="n">master_conf</span><span class="o">.</span><span class="n">push</span><span class="p">(</span><span class="s1">&#39;overlord&#39;</span><span class="p">,</span> <span class="s2">&quot;&quot;&quot;</span>
<span class="gp">... </span><span class="s2">[bar.three]</span>
<span class="gp">... </span><span class="s2">baz: emu</span>
<span class="gp">... </span><span class="s2">&quot;&quot;&quot;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">sections</span> <span class="o">=</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">master_conf</span><span class="o">.</span><span class="n">getByCategory</span><span class="p">(</span><span class="s1">&#39;bar&#39;</span><span class="p">),</span>
<span class="gp">... </span>                  <span class="n">key</span><span class="o">=</span><span class="n">attrgetter</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">))</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="n">sections</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">section</span><span class="o">.</span><span class="n">name</span><span class="p">,</span> <span class="n">section</span><span class="o">.</span><span class="n">baz</span><span class="p">)</span>
<span class="go">bar.soup cougar</span>
<span class="go">bar.three emu</span>
<span class="go">bar.two dolphin</span>
</pre></div>
</div>
<p><code class="docutils literal"><span class="pre">push()</span></code> works with master sections too.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">schema_file</span> <span class="o">=</span> <span class="n">StringIO</span><span class="p">(</span><span class="s2">&quot;&quot;&quot;</span><span class="se">\</span>
<span class="gp">... </span><span class="s2">[thing.master]</span>
<span class="gp">... </span><span class="s2">foo: 0</span>
<span class="gp">... </span><span class="s2">bar: 0</span>
<span class="gp">... </span><span class="s2">&quot;&quot;&quot;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">push_schema</span> <span class="o">=</span> <span class="n">ConfigSchema</span><span class="p">(</span><span class="s1">&#39;schema.cfg&#39;</span><span class="p">,</span> <span class="n">schema_file</span><span class="p">)</span>

<span class="gp">&gt;&gt;&gt; </span><span class="n">config_file</span> <span class="o">=</span> <span class="n">StringIO</span><span class="p">(</span><span class="s2">&quot;&quot;&quot;</span><span class="se">\</span>
<span class="gp">... </span><span class="s2">[thing.one]</span>
<span class="gp">... </span><span class="s2">foo: 1</span>
<span class="gp">... </span><span class="s2">&quot;&quot;&quot;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">push_config</span> <span class="o">=</span> <span class="n">push_schema</span><span class="o">.</span><span class="n">loadFile</span><span class="p">(</span><span class="n">config_file</span><span class="p">,</span> <span class="s1">&#39;config.cfg&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">push_config</span><span class="o">.</span><span class="n">thing</span><span class="o">.</span><span class="n">one</span><span class="o">.</span><span class="n">foo</span><span class="p">)</span>
<span class="go">1</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">push_config</span><span class="o">.</span><span class="n">thing</span><span class="o">.</span><span class="n">one</span><span class="o">.</span><span class="n">bar</span><span class="p">)</span>
<span class="go">0</span>

<span class="gp">&gt;&gt;&gt; </span><span class="n">push_config</span><span class="o">.</span><span class="n">push</span><span class="p">(</span><span class="s1">&#39;test.cfg&#39;</span><span class="p">,</span> <span class="s2">&quot;&quot;&quot;</span><span class="se">\</span>
<span class="gp">... </span><span class="s2">[thing.one]</span>
<span class="gp">... </span><span class="s2">bar: 2</span>
<span class="gp">... </span><span class="s2">&quot;&quot;&quot;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">push_config</span><span class="o">.</span><span class="n">thing</span><span class="o">.</span><span class="n">one</span><span class="o">.</span><span class="n">foo</span><span class="p">)</span>
<span class="go">1</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">push_config</span><span class="o">.</span><span class="n">thing</span><span class="o">.</span><span class="n">one</span><span class="o">.</span><span class="n">bar</span><span class="p">)</span>
<span class="go">2</span>
</pre></div>
</div>
</div>
<div class="section" id="pop">
<h2>pop()<a class="headerlink" href="#pop" title="Permalink to this headline"></a></h2>
<p>ConfigData can be removed from the stack of overlays using the <code class="docutils literal"><span class="pre">pop()</span></code>
method.  The methods returns the list of ConfigData that was removed &#8211; a
slice from the specified ConfigData to the top of the stack.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">overlays</span> <span class="o">=</span> <span class="n">config</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">&#39;test config&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">config_data</span> <span class="ow">in</span> <span class="n">overlays</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">config_data</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">extender.conf</span>
<span class="go">base.conf</span>
<span class="go">test app_a</span>
<span class="go">test config</span>

<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">config_data</span> <span class="ow">in</span> <span class="n">config</span><span class="o">.</span><span class="n">overlays</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">config_data</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">local.conf</span>
<span class="go">shared.conf</span>
<span class="go">base.conf</span>
</pre></div>
</div>
<p>The config&#8217;s state was restored to the ConfigData that is on top of the
overlay stack.  Section <code class="docutils literal"><span class="pre">section_3.app_a</span></code> was removed completely.  The keys
(<code class="docutils literal"><span class="pre">key1</span></code> and <code class="docutils literal"><span class="pre">key5</span></code>) for <code class="docutils literal"><span class="pre">section_1</span></code> were restored.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">config</span><span class="p">,</span> <span class="n">key</span><span class="o">=</span><span class="n">attrgetter</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">)):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">section</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="go">section-2.app-b</span>
<span class="go">section-5</span>
<span class="go">section_1</span>
<span class="go">section_3.app_b</span>
<span class="go">section_33</span>

<span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">key</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">]):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">key</span><span class="p">,</span> <span class="s1">&#39;:&#39;</span><span class="p">,</span> <span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">][</span><span class="n">key</span><span class="p">])</span>
<span class="go">key1 : foo</span>
<span class="go">key2 : sharing is fun</span>
<span class="go">key3 : Launchpad&amp;nbsp;rocks</span>
<span class="go">key4 : F&amp;#028c;k yeah!</span>
<span class="go">key5 : local value</span>
</pre></div>
</div>
<p>A Config must have at least one ConfigData in the overlays stack so that it
has data.  The bottom ConfigData in the overlays was made from the schema&#8217;s
required sections.  It cannot be removed by the <code class="docutils literal"><span class="pre">pop()</span></code> method.</p>
<p>If all but the bottom ConfigData is popped from overlays, the extends
property returns None.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">overlays</span> <span class="o">=</span> <span class="n">config</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">&#39;shared.conf&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">config</span><span class="o">.</span><span class="n">extends</span><span class="p">)</span>
<span class="go">None</span>
</pre></div>
</div>
</div>
<div class="section" id="attribute-access-to-config-data">
<h2>Attribute access to config data<a class="headerlink" href="#attribute-access-to-config-data" title="Permalink to this headline"></a></h2>
<p>Config provides attribute-based access to its members.  So long as the
section, category, and key names conform to Python identifier naming rules,
they can be accessed as attributes.  The Python code will not compile, or will
cause a runtime error if the object being accessed has a bad name.</p>
<p>Sections appear to be attributes of the config.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">config</span> <span class="o">=</span> <span class="n">schema</span><span class="o">.</span><span class="n">load</span><span class="p">(</span><span class="n">local_conf</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">section_1</span> <span class="ow">is</span> <span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">]</span>
<span class="go">True</span>
</pre></div>
</div>
<p>Accessing an unknown section, or a section whose name is not a valid Python
identifier will raise an AttributeError.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">section</span><span class="o">-</span><span class="mi">5</span>
<span class="gt">Traceback (most recent call last):</span>
  <span class="c">...</span>
<span class="gr">AttributeError</span>: <span class="n">No section or category named section.</span>
</pre></div>
</div>
<p>Categories may be accessed as attributes too.  The ICategory interface
provides access to its sections as members.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config.interfaces</span> <span class="k">import</span> <span class="n">ICategory</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config_category</span> <span class="o">=</span> <span class="n">config</span><span class="o">.</span><span class="n">section_3</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">ICategory</span><span class="p">,</span> <span class="n">config_category</span><span class="p">)</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config_category</span><span class="o">.</span><span class="n">app_b</span> <span class="ow">is</span> <span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_3.app_b&#39;</span><span class="p">]</span>
<span class="go">True</span>
</pre></div>
</div>
<p>Like a config, a category will raise an AttributeError if it does not have a
section that matches the identifier name.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">config_category</span><span class="o">.</span><span class="n">no_such_section</span>
<span class="gt">Traceback (most recent call last):</span>
  <span class="c">...</span>
<span class="gr">AttributeError</span>: <span class="n">No section named no_such_section.</span>
</pre></div>
</div>
<p>Section keys can be accessed directly as members.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">config</span><span class="o">.</span><span class="n">section_1</span><span class="o">.</span><span class="n">key2</span><span class="p">)</span>
<span class="go">sharing is fun</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">config</span><span class="o">.</span><span class="n">section_3</span><span class="o">.</span><span class="n">app_b</span><span class="o">.</span><span class="n">key2</span><span class="p">)</span>
<span class="go">changed</span>
</pre></div>
</div>
<p>Accessing a non-existent section key as an attribute will raise an
AttributeError.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="o">.</span><span class="n">section_1</span><span class="o">.</span><span class="n">non_key</span>
<span class="gt">Traceback (most recent call last):</span>
  <span class="c">...</span>
<span class="gr">AttributeError</span>: <span class="n">No section key named non_key.</span>
</pre></div>
</div>
</div>
<div class="section" id="implicit-data-typing">
<h2>Implicit data typing<a class="headerlink" href="#implicit-data-typing" title="Permalink to this headline"></a></h2>
<p>The ImplicitTypeSchema can create configs that support implicit datatypes.
The value of a Section key is automatically converted from <code class="docutils literal"><span class="pre">str</span></code> to the type
the value appears to be.  Implicit typing does not add any validation support;
it adds type casting conveniences for the developer.</p>
<p>An ImplicitTypeSchema can be used to parse the same schema and conf files that
Schema uses.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config</span> <span class="k">import</span> <span class="n">ImplicitTypeSchema</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">implicit_schema</span> <span class="o">=</span> <span class="n">ImplicitTypeSchema</span><span class="p">(</span><span class="n">base_conf</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">IConfigSchema</span><span class="p">,</span> <span class="n">implicit_schema</span><span class="p">)</span>
<span class="go">True</span>
</pre></div>
</div>
<p>The config loaded by ImplicitTypeSchema is the same class with the same
sections as is made by Schema.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">implicit_config</span> <span class="o">=</span> <span class="n">implicit_schema</span><span class="o">.</span><span class="n">load</span><span class="p">(</span><span class="n">local_conf</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">implicit_config</span>
<span class="go">&lt;lazr.config...Config object at ...&gt;</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span>
<span class="go">&lt;lazr.config...Config object at ...&gt;</span>

<span class="gp">&gt;&gt;&gt; </span><span class="n">sections</span> <span class="o">=</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">section</span><span class="o">.</span><span class="n">name</span> <span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="n">config</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">implicit_sections</span> <span class="o">=</span> <span class="nb">sorted</span><span class="p">(</span>
<span class="gp">... </span>    <span class="n">section</span><span class="o">.</span><span class="n">name</span> <span class="k">for</span> <span class="n">section</span> <span class="ow">in</span> <span class="n">implicit_config</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">implicit_sections</span> <span class="o">==</span> <span class="n">sections</span>
<span class="go">True</span>

<span class="gp">&gt;&gt;&gt; </span><span class="n">verifyObject</span><span class="p">(</span><span class="n">ISection</span><span class="p">,</span> <span class="n">implicit_config</span><span class="p">[</span><span class="s1">&#39;section_3.app_b&#39;</span><span class="p">])</span>
<span class="go">True</span>
</pre></div>
</div>
<p>But the type of sections in the config support implicit typing.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">implicit_config</span><span class="p">[</span><span class="s1">&#39;section_3.app_b&#39;</span><span class="p">]</span>
<span class="go">&lt;lazr.config...ImplicitTypeSection object at ...&gt;</span>
</pre></div>
</div>
<p>ImplicitTypeSection, in contrast to Section, converts values that appear to be
integer or boolean into ints and bools.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="p">[</span><span class="s1">&#39;section_3.app_b&#39;</span><span class="p">][</span><span class="s1">&#39;key1&#39;</span><span class="p">]</span>
<span class="go">&#39;17&#39;</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">implicit_config</span><span class="p">[</span><span class="s1">&#39;section_3.app_b&#39;</span><span class="p">][</span><span class="s1">&#39;key1&#39;</span><span class="p">]</span>
<span class="go">17</span>

<span class="gp">&gt;&gt;&gt; </span><span class="n">config</span><span class="p">[</span><span class="s1">&#39;section-2.app-b&#39;</span><span class="p">][</span><span class="s1">&#39;key1&#39;</span><span class="p">]</span>
<span class="go">&#39;True&#39;</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">implicit_config</span><span class="p">[</span><span class="s1">&#39;section-2.app-b&#39;</span><span class="p">][</span><span class="s1">&#39;key1&#39;</span><span class="p">]</span>
<span class="go">True</span>
</pre></div>
</div>
<p>The value is also converted when it is accessed as an attribute.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">implicit_config</span><span class="o">.</span><span class="n">section_3</span><span class="o">.</span><span class="n">app_b</span><span class="o">.</span><span class="n">key1</span>
<span class="go">17</span>
</pre></div>
</div>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">implicit_config</span><span class="p">[</span><span class="s1">&#39;section-2.app-b&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">key1</span>
<span class="go">True</span>
</pre></div>
</div>
<p>ImplicitTypeSection uses a private method that employs heuristic rules to
convert strings into simple types.  It may return a str, bool, or int.  When
the argument is the word &#8216;true&#8217; or &#8216;false&#8217; (in any case), a bool is returned.
Values like &#8216;yes&#8217;, &#8216;no&#8217;, &#8216;0&#8217;, and &#8216;1&#8217; are not converted to bool.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">convert</span> <span class="o">=</span> <span class="n">implicit_config</span><span class="p">[</span><span class="s1">&#39;section_1&#39;</span><span class="p">]</span><span class="o">.</span><span class="n">_convert</span>

<span class="gp">&gt;&gt;&gt; </span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;false&#39;</span><span class="p">)</span>
<span class="go">False</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;TRUE&#39;</span><span class="p">)</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;tRue&#39;</span><span class="p">)</span>
<span class="go">True</span>

<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;yes&#39;</span><span class="p">))</span>
<span class="go">yes</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;1&#39;</span><span class="p">)</span>
<span class="go">1</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;True or False&#39;</span><span class="p">))</span>
<span class="go">True or False</span>
</pre></div>
</div>
<p>When the argument is the word <code class="docutils literal"><span class="pre">none</span></code>, <code class="docutils literal"><span class="pre">None</span></code> is returned.  The token in
the config means the key has no value.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;none&#39;</span><span class="p">))</span>
<span class="go">None</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;None&#39;</span><span class="p">))</span>
<span class="go">None</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;nonE&#39;</span><span class="p">))</span>
<span class="go">None</span>

<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;none today&#39;</span><span class="p">))</span>
<span class="go">none today</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;nonevident&#39;</span><span class="p">))</span>
<span class="go">nonevident</span>
</pre></div>
</div>
<p>When the argument is an unbroken sequence of numbers, an int is returned.  The
number may have a leading positive or negative.  Octal and hex notation is not
supported.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;0&#39;</span><span class="p">)</span>
<span class="go">0</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;2001&#39;</span><span class="p">)</span>
<span class="go">2001</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;-55&#39;</span><span class="p">)</span>
<span class="go">-55</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;+404&#39;</span><span class="p">)</span>
<span class="go">404</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;0100&#39;</span><span class="p">)</span>
<span class="go">100</span>

<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;2001-01-01&#39;</span><span class="p">))</span>
<span class="go">2001-01-01</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;1000*60*5&#39;</span><span class="p">))</span>
<span class="go">1000*60*5</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;1000 * 60 * 5&#39;</span><span class="p">))</span>
<span class="go">1000 * 60 * 5</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;1,024&#39;</span><span class="p">))</span>
<span class="go">1,024</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;0.5&#39;</span><span class="p">))</span>
<span class="go">0.5</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s1">&#39;0x100&#39;</span><span class="p">))</span>
<span class="go">0x100</span>
</pre></div>
</div>
<p>Multiline values are always strings, with white space (and line breaks)
removed from the beginning and end.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">convert</span><span class="p">(</span><span class="s2">&quot;&quot;&quot;multiline value 1</span>
<span class="gp">... </span><span class="s2">    multiline value 2&quot;&quot;&quot;</span><span class="p">))</span>
<span class="go">multiline value 1</span>
<span class="go">multiline value 2</span>
</pre></div>
</div>
</div>
<div class="section" id="type-conversion-helpers">
<h2>Type conversion helpers<a class="headerlink" href="#type-conversion-helpers" title="Permalink to this headline"></a></h2>
<p>lazr.config provides a few helpers for doing explicit type conversion.  These
functions have to be imported and called explicitly on the configuration
variable values.</p>
<div class="section" id="booleans">
<h3>Booleans<a class="headerlink" href="#booleans" title="Permalink to this headline"></a></h3>
<p>There is a helper for turning various strings into the boolean values <code class="docutils literal"><span class="pre">True</span></code>
and <code class="docutils literal"><span class="pre">False</span></code>.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config</span> <span class="k">import</span> <span class="n">as_boolean</span>
</pre></div>
</div>
<p>True values include (case-insensitively): true, yes, 1, on, enabled, and
enable.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">value</span> <span class="ow">in</span> <span class="p">(</span><span class="s1">&#39;true&#39;</span><span class="p">,</span> <span class="s1">&#39;yes&#39;</span><span class="p">,</span> <span class="s1">&#39;on&#39;</span><span class="p">,</span> <span class="s1">&#39;enable&#39;</span><span class="p">,</span> <span class="s1">&#39;enabled&#39;</span><span class="p">,</span> <span class="s1">&#39;1&#39;</span><span class="p">):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="s1">&#39;-&gt;&#39;</span><span class="p">,</span> <span class="n">as_boolean</span><span class="p">(</span><span class="n">value</span><span class="p">))</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">value</span><span class="o">.</span><span class="n">upper</span><span class="p">(),</span> <span class="s1">&#39;-&gt;&#39;</span><span class="p">,</span> <span class="n">as_boolean</span><span class="p">(</span><span class="n">value</span><span class="o">.</span><span class="n">upper</span><span class="p">()))</span>
<span class="go">true -&gt; True</span>
<span class="go">TRUE -&gt; True</span>
<span class="go">yes -&gt; True</span>
<span class="go">YES -&gt; True</span>
<span class="go">on -&gt; True</span>
<span class="go">ON -&gt; True</span>
<span class="go">enable -&gt; True</span>
<span class="go">ENABLE -&gt; True</span>
<span class="go">enabled -&gt; True</span>
<span class="go">ENABLED -&gt; True</span>
<span class="go">1 -&gt; True</span>
<span class="go">1 -&gt; True</span>
</pre></div>
</div>
<p>False values include (case-insensitively): false, no, 0, off, disabled, and
disable.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">value</span> <span class="ow">in</span> <span class="p">(</span><span class="s1">&#39;false&#39;</span><span class="p">,</span> <span class="s1">&#39;no&#39;</span><span class="p">,</span> <span class="s1">&#39;off&#39;</span><span class="p">,</span> <span class="s1">&#39;disable&#39;</span><span class="p">,</span> <span class="s1">&#39;disabled&#39;</span><span class="p">,</span> <span class="s1">&#39;0&#39;</span><span class="p">):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="s1">&#39;-&gt;&#39;</span><span class="p">,</span> <span class="n">as_boolean</span><span class="p">(</span><span class="n">value</span><span class="p">))</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">value</span><span class="o">.</span><span class="n">upper</span><span class="p">(),</span> <span class="s1">&#39;-&gt;&#39;</span><span class="p">,</span> <span class="n">as_boolean</span><span class="p">(</span><span class="n">value</span><span class="o">.</span><span class="n">upper</span><span class="p">()))</span>
<span class="go">false -&gt; False</span>
<span class="go">FALSE -&gt; False</span>
<span class="go">no -&gt; False</span>
<span class="go">NO -&gt; False</span>
<span class="go">off -&gt; False</span>
<span class="go">OFF -&gt; False</span>
<span class="go">disable -&gt; False</span>
<span class="go">DISABLE -&gt; False</span>
<span class="go">disabled -&gt; False</span>
<span class="go">DISABLED -&gt; False</span>
<span class="go">0 -&gt; False</span>
<span class="go">0 -&gt; False</span>
</pre></div>
</div>
<p>Anything else is a error.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_boolean</span><span class="p">(</span><span class="s1">&#39;cheese&#39;</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
<span class="c">...</span>
<span class="gr">ValueError</span>: <span class="n">Invalid boolean value: cheese</span>
</pre></div>
</div>
</div>
<div class="section" id="host-and-port">
<h3>Host and port<a class="headerlink" href="#host-and-port" title="Permalink to this headline"></a></h3>
<p>There is a helper for converting from a <code class="docutils literal"><span class="pre">host:port</span></code> string to a 2-tuple of
<code class="docutils literal"><span class="pre">(host,</span> <span class="pre">port)</span></code>.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config</span> <span class="k">import</span> <span class="n">as_host_port</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">host</span><span class="p">,</span> <span class="n">port</span> <span class="o">=</span> <span class="n">as_host_port</span><span class="p">(</span><span class="s1">&#39;host:25&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">host</span><span class="p">,</span> <span class="n">port</span><span class="p">)</span>
<span class="go">host 25</span>
</pre></div>
</div>
<p>The port string is optional, in which case, port 25 is the default (for
historical reasons).</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">host</span><span class="p">,</span> <span class="n">port</span> <span class="o">=</span> <span class="n">as_host_port</span><span class="p">(</span><span class="s1">&#39;host&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">host</span><span class="p">,</span> <span class="n">port</span><span class="p">)</span>
<span class="go">host 25</span>
</pre></div>
</div>
<p>The default port can be overridden.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">host</span><span class="p">,</span> <span class="n">port</span> <span class="o">=</span> <span class="n">as_host_port</span><span class="p">(</span><span class="s1">&#39;host&#39;</span><span class="p">,</span> <span class="n">default_port</span><span class="o">=</span><span class="mi">22</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">host</span><span class="p">,</span> <span class="n">port</span><span class="p">)</span>
<span class="go">host 22</span>
</pre></div>
</div>
<p>The default port is ignored if it is given in the value.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">host</span><span class="p">,</span> <span class="n">port</span> <span class="o">=</span> <span class="n">as_host_port</span><span class="p">(</span><span class="s1">&#39;host:80&#39;</span><span class="p">,</span> <span class="n">default_port</span><span class="o">=</span><span class="mi">22</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">host</span><span class="p">,</span> <span class="n">port</span><span class="p">)</span>
<span class="go">host 80</span>
</pre></div>
</div>
<p>The host name is also optional, as denoted by a leading colon.  When omitted,
localhost is used.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">host</span><span class="p">,</span> <span class="n">port</span> <span class="o">=</span> <span class="n">as_host_port</span><span class="p">(</span><span class="s1">&#39;:80&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">host</span><span class="p">,</span> <span class="n">port</span><span class="p">)</span>
<span class="go">localhost 80</span>
</pre></div>
</div>
<p>The default host name can be overridden though.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">host</span><span class="p">,</span> <span class="n">port</span> <span class="o">=</span> <span class="n">as_host_port</span><span class="p">(</span><span class="s1">&#39;:80&#39;</span><span class="p">,</span> <span class="n">default_host</span><span class="o">=</span><span class="s1">&#39;myhost&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">host</span><span class="p">,</span> <span class="n">port</span><span class="p">)</span>
<span class="go">myhost 80</span>
</pre></div>
</div>
<p>The default host name is ignored if the value string contains it.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">host</span><span class="p">,</span> <span class="n">port</span> <span class="o">=</span> <span class="n">as_host_port</span><span class="p">(</span><span class="s1">&#39;yourhost:80&#39;</span><span class="p">,</span> <span class="n">default_host</span><span class="o">=</span><span class="s1">&#39;myhost&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">host</span><span class="p">,</span> <span class="n">port</span><span class="p">)</span>
<span class="go">yourhost 80</span>
</pre></div>
</div>
<p>A ValueError occurs if the port number in the configuration value string is
not an integer.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_host_port</span><span class="p">(</span><span class="s1">&#39;:foo&#39;</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
<span class="c">...</span>
<span class="gr">ValueError</span>: <span class="n">invalid literal for int...foo...</span>
</pre></div>
</div>
</div>
<div class="section" id="user-and-group">
<h3>User and group<a class="headerlink" href="#user-and-group" title="Permalink to this headline"></a></h3>
<p>A helper is provided for turning a <code class="docutils literal"><span class="pre">chown(1)</span></code>-style <code class="docutils literal"><span class="pre">user:group</span></code>
specification into a 2-tuple of the user name and group name.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config</span> <span class="k">import</span> <span class="n">as_username_groupname</span>
</pre></div>
</div>
<p>The value string must contain both a user name and group name, separated by a
colon, otherwise an exception is raised.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_username_groupname</span><span class="p">(</span><span class="s1">&#39;foo&#39;</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
<span class="c">...</span>
<span class="gr">ValueError</span>: <span class="n">...</span>
</pre></div>
</div>
<p>When both are given, the strings are returned unchanged or validated.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">user</span><span class="p">,</span> <span class="n">group</span> <span class="o">=</span> <span class="n">as_username_groupname</span><span class="p">(</span><span class="s1">&#39;person:group&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">user</span><span class="p">,</span> <span class="n">group</span><span class="p">)</span>
<span class="go">person group</span>
</pre></div>
</div>
<p>Numeric values can be given, but they are not converted into their symbolic
names.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">uid</span><span class="p">,</span> <span class="n">gid</span> <span class="o">=</span> <span class="n">as_username_groupname</span><span class="p">(</span><span class="s1">&#39;25:26&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">uid</span><span class="p">,</span> <span class="n">gid</span><span class="p">)</span>
<span class="go">25 26</span>
</pre></div>
</div>
<p>By default the current user and group names are returned.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">grp</span><span class="o">,</span> <span class="nn">os</span><span class="o">,</span> <span class="nn">pwd</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">user</span><span class="p">,</span> <span class="n">group</span> <span class="o">=</span> <span class="n">as_username_groupname</span><span class="p">()</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">user</span> <span class="o">==</span> <span class="n">pwd</span><span class="o">.</span><span class="n">getpwuid</span><span class="p">(</span><span class="n">os</span><span class="o">.</span><span class="n">getuid</span><span class="p">())</span><span class="o">.</span><span class="n">pw_name</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">group</span> <span class="o">==</span> <span class="n">grp</span><span class="o">.</span><span class="n">getgrgid</span><span class="p">(</span><span class="n">os</span><span class="o">.</span><span class="n">getgid</span><span class="p">())</span><span class="o">.</span><span class="n">gr_name</span>
<span class="go">True</span>
</pre></div>
</div>
</div>
<div class="section" id="time-intervals">
<h3>Time intervals<a class="headerlink" href="#time-intervals" title="Permalink to this headline"></a></h3>
<p>This converter accepts a range of <em>time interval specifications</em>, and returns
a Python <a class="reference external" href="http://docs.python.org/3/library/datetime.html#timedelta-objects">timedelta</a>.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config</span> <span class="k">import</span> <span class="n">as_timedelta</span>
</pre></div>
</div>
<p>The function converts from an integer to the equivalent number of seconds.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;45s&#39;</span><span class="p">)</span>
<span class="go">datetime.timedelta(0, 45)</span>
</pre></div>
</div>
<p>The function also accepts suffixes <code class="docutils literal"><span class="pre">m</span></code> for minutes...</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;3m&#39;</span><span class="p">)</span>
<span class="go">datetime.timedelta(0, 180)</span>
</pre></div>
</div>
<p>...``h`` for hours...</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;2h&#39;</span><span class="p">)</span>
<span class="go">datetime.timedelta(0, 7200)</span>
</pre></div>
</div>
<p>...and <code class="docutils literal"><span class="pre">d</span></code> for days...</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;4d&#39;</span><span class="p">)</span>
<span class="go">datetime.timedelta(4)</span>
</pre></div>
</div>
<p>...and <code class="docutils literal"><span class="pre">w</span></code> for weeks.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;4w&#39;</span><span class="p">)</span>
<span class="go">datetime.timedelta(28)</span>
</pre></div>
</div>
<p>The function accepts a fractional number of seconds, indicating microseconds.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;3.2s&#39;</span><span class="p">)</span>
<span class="go">datetime.timedelta(0, 3, 200000)</span>
</pre></div>
</div>
<p>It also accepts any combination thereof.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;3m22.5s&#39;</span><span class="p">)</span>
<span class="go">datetime.timedelta(0, 202, 500000)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;4w2d9h3s&#39;</span><span class="p">)</span>
<span class="go">datetime.timedelta(30, 32403)</span>
</pre></div>
</div>
<p>But doesn&#8217;t accept &#8220;weird&#8221; or duplicate combinations.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;3s2s&#39;</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
<span class="c">...</span>
<span class="gr">ValueError</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;2.9s4w&#39;</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
<span class="c">...</span>
<span class="gr">ValueError</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;m&#39;</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
<span class="c">...</span>
<span class="gr">ValueError</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;3m2&#39;</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
<span class="c">...</span>
<span class="gr">ValueError</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;45&#39;</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
<span class="c">...</span>
<span class="gr">ValueError</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;45wm&#39;</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
<span class="c">...</span>
<span class="gr">ValueError</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">as_timedelta</span><span class="p">(</span><span class="s1">&#39;45z&#39;</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
<span class="c">...</span>
<span class="gr">ValueError</span>
</pre></div>
</div>
</div>
<div class="section" id="log-levels">
<h3>Log levels<a class="headerlink" href="#log-levels" title="Permalink to this headline"></a></h3>
<p>It&#8217;s convenient to be able to use symbolic log level names when using
<code class="docutils literal"><span class="pre">lazr.config</span></code> to configure the Python logger.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">lazr.config</span> <span class="k">import</span> <span class="n">as_log_level</span>
</pre></div>
</div>
<p>Any symbolic log level value is valid to use, case insensitively.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">for</span> <span class="n">value</span> <span class="ow">in</span> <span class="p">(</span><span class="s1">&#39;critical&#39;</span><span class="p">,</span> <span class="s1">&#39;error&#39;</span><span class="p">,</span> <span class="s1">&#39;warning&#39;</span><span class="p">,</span> <span class="s1">&#39;info&#39;</span><span class="p">,</span>
<span class="gp">... </span>              <span class="s1">&#39;debug&#39;</span><span class="p">,</span> <span class="s1">&#39;notset&#39;</span><span class="p">):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="s1">&#39;-&gt;&#39;</span><span class="p">,</span> <span class="n">as_log_level</span><span class="p">(</span><span class="n">value</span><span class="p">))</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">value</span><span class="o">.</span><span class="n">upper</span><span class="p">(),</span> <span class="s1">&#39;-&gt;&#39;</span><span class="p">,</span> <span class="n">as_log_level</span><span class="p">(</span><span class="n">value</span><span class="o">.</span><span class="n">upper</span><span class="p">()))</span>
<span class="go">critical -&gt; 50</span>
<span class="go">CRITICAL -&gt; 50</span>
<span class="go">error -&gt; 40</span>
<span class="go">ERROR -&gt; 40</span>
<span class="go">warning -&gt; 30</span>
<span class="go">WARNING -&gt; 30</span>
<span class="go">info -&gt; 20</span>
<span class="go">INFO -&gt; 20</span>
<span class="go">debug -&gt; 10</span>
<span class="go">DEBUG -&gt; 10</span>
<span class="go">notset -&gt; 0</span>
<span class="go">NOTSET -&gt; 0</span>
</pre></div>
</div>
<p>Non-log levels cannot be used here.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">as_log_level</span><span class="p">(</span><span class="s1">&#39;cheese&#39;</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
<span class="c">...</span>
<span class="gr">AttributeError</span>: <span class="n">...</span>
</pre></div>
</div>
</div>
</div>
<div class="section" id="other-documents">
<h2>Other Documents<a class="headerlink" href="#other-documents" title="Permalink to this headline"></a></h2>
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<li class="toctree-l2"><a class="reference internal" href="NEWS.html#id2">2.1 (2015-01-05)</a></li>
<li class="toctree-l2"><a class="reference internal" href="NEWS.html#id3">2.0.1 (2014-08-22)</a></li>
<li class="toctree-l2"><a class="reference internal" href="NEWS.html#id4">2.0 (2013-01-10)</a></li>
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  <h3><a href="../../../../README.html">Table Of Contents</a></h3>
  <ul>
<li><a class="reference internal" href="#">LAZR config</a><ul>
<li><a class="reference internal" href="#configschema">ConfigSchema</a></li>
<li><a class="reference internal" href="#schemasection">SchemaSection</a></li>
<li><a class="reference internal" href="#configschema-validation">ConfigSchema validation</a></li>
<li><a class="reference internal" href="#iconfigloader">IConfigLoader</a></li>
<li><a class="reference internal" href="#config">Config</a></li>
<li><a class="reference internal" href="#section">Section</a></li>
<li><a class="reference internal" href="#validating-configs">Validating configs</a></li>
<li><a class="reference internal" href="#config-overlays">Config overlays</a></li>
<li><a class="reference internal" href="#push">push()</a></li>
<li><a class="reference internal" href="#pop">pop()</a></li>
<li><a class="reference internal" href="#attribute-access-to-config-data">Attribute access to config data</a></li>
<li><a class="reference internal" href="#implicit-data-typing">Implicit data typing</a></li>
<li><a class="reference internal" href="#type-conversion-helpers">Type conversion helpers</a><ul>
<li><a class="reference internal" href="#booleans">Booleans</a></li>
<li><a class="reference internal" href="#host-and-port">Host and port</a></li>
<li><a class="reference internal" href="#user-and-group">User and group</a></li>
<li><a class="reference internal" href="#time-intervals">Time intervals</a></li>
<li><a class="reference internal" href="#log-levels">Log levels</a></li>
</ul>
</li>
<li><a class="reference internal" href="#other-documents">Other Documents</a></li>
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