/usr/lib/python3/dist-packages/tenacity-4.8.0.egg-info/PKG-INFO is in python3-tenacity 4.8.0-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 | Metadata-Version: 1.1
Name: tenacity
Version: 4.8.0
Summary: Retry code until it succeeeds
Home-page: https://github.com/jd/tenacity
Author: Julien Danjou
Author-email: julien@danjou.info
License: UNKNOWN
Description-Content-Type: UNKNOWN
Description: Tenacity
========
.. image:: https://img.shields.io/pypi/v/tenacity.svg
:target: https://pypi.python.org/pypi/tenacity
.. image:: https://img.shields.io/travis/jd/tenacity.svg
:target: https://travis-ci.org/jd/tenacity
.. image:: https://img.shields.io/badge/SayThanks.io-%E2%98%BC-1EAEDB.svg
:target: https://saythanks.io/to/jd
Tenacity is an Apache 2.0 licensed general-purpose retrying library, written in
Python, to simplify the task of adding retry behavior to just about anything.
It originates from `a fork of retrying
<https://github.com/rholder/retrying/issues/65>`_.
The simplest use case is retrying a flaky function whenever an `Exception`
occurs until a value is returned.
.. testcode::
import random
from tenacity import retry
@retry
def do_something_unreliable():
if random.randint(0, 10) > 1:
raise IOError("Broken sauce, everything is hosed!!!111one")
else:
return "Awesome sauce!"
print(do_something_unreliable())
.. testoutput::
:hide:
Awesome sauce!
Features
--------
- Generic Decorator API
- Specify stop condition (i.e. limit by number of attempts)
- Specify wait condition (i.e. exponential backoff sleeping between attempts)
- Customize retrying on Exceptions
- Customize retrying on expected returned result
- Retry on coroutines
Installation
------------
To install *tenacity*, simply:
.. code-block:: bash
$ pip install tenacity
Examples
----------
.. testsetup:: *
import logging
from tenacity import *
class MyException(Exception):
pass
As you saw above, the default behavior is to retry forever without waiting when
an exception is raised.
.. testcode::
@retry
def never_give_up_never_surrender():
print("Retry forever ignoring Exceptions, don't wait between retries")
raise Exception
Let's be a little less persistent and set some boundaries, such as the number
of attempts before giving up.
.. testcode::
@retry(stop=stop_after_attempt(7))
def stop_after_7_attempts():
print("Stopping after 7 attempts")
raise Exception
We don't have all day, so let's set a boundary for how long we should be
retrying stuff.
.. testcode::
@retry(stop=stop_after_delay(10))
def stop_after_10_s():
print("Stopping after 10 seconds")
raise Exception
You can combine several stop conditions by using the `|` operator:
.. testcode::
@retry(stop=(stop_after_delay(10) | stop_after_attempt(5)))
def stop_after_10_s_or_5_retries():
print("Stopping after 10 seconds or 5 retries")
raise Exception
Most things don't like to be polled as fast as possible, so let's just wait 2
seconds between retries.
.. testcode::
@retry(wait=wait_fixed(2))
def wait_2_s():
print("Wait 2 second between retries")
raise Exception
Some things perform best with a bit of randomness injected.
.. testcode::
@retry(wait=wait_random(min=1, max=2))
def wait_random_1_to_2_s():
print("Randomly wait 1 to 2 seconds between retries")
raise Exception
Then again, it's hard to beat exponential backoff when retrying distributed
services and other remote endpoints.
.. testcode::
@retry(wait=wait_exponential(multiplier=1, max=10))
def wait_exponential_1():
print("Wait 2^x * 1 second between each retry, up to 10 seconds, then 10 seconds afterwards")
raise Exception
Then again, it's also hard to beat combining fixed waits and jitter (to
help avoid thundering herds) when retrying distributed services and other
remote endpoints.
.. testcode::
@retry(wait=wait_fixed(3) + wait_random(0, 2))
def wait_fixed_jitter():
print("Wait at least 3 seconds, and add up to 2 seconds of random delay")
raise Exception
When multiple processes are in contention for a shared resource, exponentially
increasing jitter helps minimise collisions.
.. testcode::
@retry(wait=wait_random_exponential(multiplier=1, max=60))
def wait_exponential_jitter():
print("Randomly wait up to 2^x * 1 seconds between each retry until the range reaches 60 seconds, then randomly up to 60 seconds afterwards")
raise Exception
Sometimes it's necessary to build a chain of backoffs.
.. testcode::
@retry(wait=wait_chain(*[wait_fixed(3) for i in range(3)] +
[wait_fixed(7) for i in range(2)] +
[wait_fixed(9)]))
def wait_fixed_chained():
print("Wait 3s for 3 attempts, 7s for the next 2 attempts and 9s for all attempts thereafter")
raise Exception
We have a few options for dealing with retries that raise specific or general
exceptions, as in the cases here.
.. testcode::
@retry(retry=retry_if_exception_type(IOError))
def might_io_error():
print("Retry forever with no wait if an IOError occurs, raise any other errors")
raise Exception
We can also use the result of the function to alter the behavior of retrying.
.. testcode::
def is_none_p(value):
"""Return True if value is None"""
return value is None
@retry(retry=retry_if_result(is_none_p))
def might_return_none():
print("Retry with no wait if return value is None")
We can also combine several conditions:
.. testcode::
def is_none_p(value):
"""Return True if value is None"""
return value is None
@retry(retry=(retry_if_result(is_none_p) | retry_if_exception_type()))
def might_return_none():
print("Retry forever ignoring Exceptions with no wait if return value is None")
Any combination of stop, wait, etc. is also supported to give you the freedom
to mix and match.
It's also possible to retry explicitly at any time by raising the `TryAgain`
exception:
.. testcode::
@retry
def do_something():
result = something_else()
if result == 23:
raise TryAgain
While callables that "timeout" retrying raise a `RetryError` by default,
we can reraise the last attempt's exception if needed:
.. testcode::
@retry(reraise=True, stop=stop_after_attempt(3))
def raise_my_exception():
raise MyException("Fail")
try:
raise_my_exception()
except MyException:
# timed out retrying
pass
It's possible to execute an action before any attempt of calling the function
by using the before callback function:
.. testcode::
logger = logging.getLogger(__name__)
@retry(stop=stop_after_attempt(3), before=before_log(logger, logging.DEBUG))
def raise_my_exception():
raise MyException("Fail")
In the same spirit, It's possible to execute after a call that failed:
.. testcode::
logger = logging.getLogger(__name__)
@retry(stop=stop_after_attempt(3), after=after_log(logger, logging.DEBUG))
def raise_my_exception():
raise MyException("Fail")
You can access the statistics about the retry made over a function by using the
`retry` attribute attached to the function and its `statistics` attribute:
.. testcode::
@retry(stop=stop_after_attempt(3))
def raise_my_exception():
raise MyException("Fail")
try:
raise_my_exception()
except Exception:
pass
print(raise_my_exception.retry.statistics)
.. testoutput::
:hide:
...
You can change the arguments of a retry decorator as needed when calling it by
using the `retry_with` function attached to the wrapped function:
.. testcode::
@retry(stop=stop_after_attempt(3))
def raise_my_exception():
raise MyException("Fail")
try:
raise_my_exception.retry_with(stop=stop_after_attempt(4))()
except Exception:
pass
print(raise_my_exception.retry.statistics)
.. testoutput::
:hide:
...
Finally, ``retry`` works also on asyncio and Tornado (>= 4.5) coroutines.
Sleeps are done asynchronously too.
.. code-block:: python
@retry
async def my_async_function(loop):
await loop.getaddrinfo('8.8.8.8', 53)
.. code-block:: python
@retry
@tornado.gen.coroutine
def my_async_function(http_client, url):
yield http_client.fetch(url)
Contribute
----------
#. Check for open issues or open a fresh issue to start a discussion around a
feature idea or a bug.
#. Fork `the repository`_ on GitHub to start making your changes to the
**master** branch (or branch off of it).
#. Write a test which shows that the bug was fixed or that the feature works as
expected.
#. Make the docs better (or more detailed, or more easier to read, or ...)
.. _`the repository`: https://github.com/jd/tenacity
Platform: UNKNOWN
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: Apache Software License
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Topic :: Utilities
|