/usr/lib/pypy/dist-packages/enum34-1.1.2.egg-info is in pypy-enum34 1.1.2-1.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 | Metadata-Version: 1.1
Name: enum34
Version: 1.1.2
Summary: Python 3.4 Enum backported to 3.3, 3.2, 3.1, 2.7, 2.6, 2.5, and 2.4
Home-page: https://pypi.python.org/pypi/enum34
Author: Ethan Furman
Author-email: ethan@stoneleaf.us
License: BSD License
Description: ``enum`` --- support for enumerations
========================================
.. :synopsis: enumerations are sets of symbolic names bound to unique, constant
values.
.. :moduleauthor:: Ethan Furman <ethan@stoneleaf.us>
.. :sectionauthor:: Barry Warsaw <barry@python.org>,
.. :sectionauthor:: Eli Bendersky <eliben@gmail.com>,
.. :sectionauthor:: Ethan Furman <ethan@stoneleaf.us>
----------------
An enumeration is a set of symbolic names (members) bound to unique, constant
values. Within an enumeration, the members can be compared by identity, and
the enumeration itself can be iterated over.
Module Contents
---------------
This module defines two enumeration classes that can be used to define unique
sets of names and values: ``Enum`` and ``IntEnum``. It also defines
one decorator, ``unique``.
``Enum``
Base class for creating enumerated constants. See section `Functional API`_
for an alternate construction syntax.
``IntEnum``
Base class for creating enumerated constants that are also subclasses of ``int``.
``unique``
Enum class decorator that ensures only one name is bound to any one value.
Creating an Enum
----------------
Enumerations are created using the ``class`` syntax, which makes them
easy to read and write. An alternative creation method is described in
`Functional API`_. To define an enumeration, subclass ``Enum`` as
follows::
>>> from enum import Enum
>>> class Color(Enum):
... red = 1
... green = 2
... blue = 3
Note: Nomenclature
- The class ``Color`` is an *enumeration* (or *enum*)
- The attributes ``Color.red``, ``Color.green``, etc., are
*enumeration members* (or *enum members*).
- The enum members have *names* and *values* (the name of
``Color.red`` is ``red``, the value of ``Color.blue`` is
``3``, etc.)
Note:
Even though we use the ``class`` syntax to create Enums, Enums
are not normal Python classes. See `How are Enums different?`_ for
more details.
Enumeration members have human readable string representations::
>>> print(Color.red)
Color.red
...while their ``repr`` has more information::
>>> print(repr(Color.red))
<Color.red: 1>
The *type* of an enumeration member is the enumeration it belongs to::
>>> type(Color.red)
<enum 'Color'>
>>> isinstance(Color.green, Color)
True
>>>
Enum members also have a property that contains just their item name::
>>> print(Color.red.name)
red
Enumerations support iteration. In Python 3.x definition order is used; in
Python 2.x the definition order is not available, but class attribute
``__order__`` is supported; otherwise, value order is used::
>>> class Shake(Enum):
... __order__ = 'vanilla chocolate cookies mint' # only needed in 2.x
... vanilla = 7
... chocolate = 4
... cookies = 9
... mint = 3
...
>>> for shake in Shake:
... print(shake)
...
Shake.vanilla
Shake.chocolate
Shake.cookies
Shake.mint
The ``__order__`` attribute is always removed, and in 3.x it is also ignored
(order is definition order); however, in the stdlib version it will be ignored
but not removed.
Enumeration members are hashable, so they can be used in dictionaries and sets::
>>> apples = {}
>>> apples[Color.red] = 'red delicious'
>>> apples[Color.green] = 'granny smith'
>>> apples == {Color.red: 'red delicious', Color.green: 'granny smith'}
True
Programmatic access to enumeration members and their attributes
---------------------------------------------------------------
Sometimes it's useful to access members in enumerations programmatically (i.e.
situations where ``Color.red`` won't do because the exact color is not known
at program-writing time). ``Enum`` allows such access::
>>> Color(1)
<Color.red: 1>
>>> Color(3)
<Color.blue: 3>
If you want to access enum members by *name*, use item access::
>>> Color['red']
<Color.red: 1>
>>> Color['green']
<Color.green: 2>
If have an enum member and need its ``name`` or ``value``::
>>> member = Color.red
>>> member.name
'red'
>>> member.value
1
Duplicating enum members and values
-----------------------------------
Having two enum members (or any other attribute) with the same name is invalid;
in Python 3.x this would raise an error, but in Python 2.x the second member
simply overwrites the first::
>>> # python 2.x
>>> class Shape(Enum):
... square = 2
... square = 3
...
>>> Shape.square
<Shape.square: 3>
>>> # python 3.x
>>> class Shape(Enum):
... square = 2
... square = 3
Traceback (most recent call last):
...
TypeError: Attempted to reuse key: 'square'
However, two enum members are allowed to have the same value. Given two members
A and B with the same value (and A defined first), B is an alias to A. By-value
lookup of the value of A and B will return A. By-name lookup of B will also
return A::
>>> class Shape(Enum):
... __order__ = 'square diamond circle alias_for_square' # only needed in 2.x
... square = 2
... diamond = 1
... circle = 3
... alias_for_square = 2
...
>>> Shape.square
<Shape.square: 2>
>>> Shape.alias_for_square
<Shape.square: 2>
>>> Shape(2)
<Shape.square: 2>
Allowing aliases is not always desirable. ``unique`` can be used to ensure
that none exist in a particular enumeration::
>>> from enum import unique
>>> @unique
... class Mistake(Enum):
... __order__ = 'one two three four' # only needed in 2.x
... one = 1
... two = 2
... three = 3
... four = 3
Traceback (most recent call last):
...
ValueError: duplicate names found in <enum 'Mistake'>: four -> three
Iterating over the members of an enum does not provide the aliases::
>>> list(Shape)
[<Shape.square: 2>, <Shape.diamond: 1>, <Shape.circle: 3>]
The special attribute ``__members__`` is a dictionary mapping names to members.
It includes all names defined in the enumeration, including the aliases::
>>> for name, member in sorted(Shape.__members__.items()):
... name, member
...
('alias_for_square', <Shape.square: 2>)
('circle', <Shape.circle: 3>)
('diamond', <Shape.diamond: 1>)
('square', <Shape.square: 2>)
The ``__members__`` attribute can be used for detailed programmatic access to
the enumeration members. For example, finding all the aliases::
>>> [name for name, member in Shape.__members__.items() if member.name != name]
['alias_for_square']
Comparisons
-----------
Enumeration members are compared by identity::
>>> Color.red is Color.red
True
>>> Color.red is Color.blue
False
>>> Color.red is not Color.blue
True
Ordered comparisons between enumeration values are *not* supported. Enum
members are not integers (but see `IntEnum`_ below)::
>>> Color.red < Color.blue
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: unorderable types: Color() < Color()
.. warning::
In Python 2 *everything* is ordered, even though the ordering may not
make sense. If you want your enumerations to have a sensible ordering
check out the `OrderedEnum`_ recipe below.
Equality comparisons are defined though::
>>> Color.blue == Color.red
False
>>> Color.blue != Color.red
True
>>> Color.blue == Color.blue
True
Comparisons against non-enumeration values will always compare not equal
(again, ``IntEnum`` was explicitly designed to behave differently, see
below)::
>>> Color.blue == 2
False
Allowed members and attributes of enumerations
----------------------------------------------
The examples above use integers for enumeration values. Using integers is
short and handy (and provided by default by the `Functional API`_), but not
strictly enforced. In the vast majority of use-cases, one doesn't care what
the actual value of an enumeration is. But if the value *is* important,
enumerations can have arbitrary values.
Enumerations are Python classes, and can have methods and special methods as
usual. If we have this enumeration::
>>> class Mood(Enum):
... funky = 1
... happy = 3
...
... def describe(self):
... # self is the member here
... return self.name, self.value
...
... def __str__(self):
... return 'my custom str! {0}'.format(self.value)
...
... @classmethod
... def favorite_mood(cls):
... # cls here is the enumeration
... return cls.happy
Then::
>>> Mood.favorite_mood()
<Mood.happy: 3>
>>> Mood.happy.describe()
('happy', 3)
>>> str(Mood.funky)
'my custom str! 1'
The rules for what is allowed are as follows: _sunder_ names (starting and
ending with a single underscore) are reserved by enum and cannot be used;
all other attributes defined within an enumeration will become members of this
enumeration, with the exception of *__dunder__* names and descriptors (methods
are also descriptors).
Note:
If your enumeration defines ``__new__`` and/or ``__init__`` then
whatever value(s) were given to the enum member will be passed into
those methods. See `Planet`_ for an example.
Restricted subclassing of enumerations
--------------------------------------
Subclassing an enumeration is allowed only if the enumeration does not define
any members. So this is forbidden::
>>> class MoreColor(Color):
... pink = 17
Traceback (most recent call last):
...
TypeError: Cannot extend enumerations
But this is allowed::
>>> class Foo(Enum):
... def some_behavior(self):
... pass
...
>>> class Bar(Foo):
... happy = 1
... sad = 2
...
Allowing subclassing of enums that define members would lead to a violation of
some important invariants of types and instances. On the other hand, it makes
sense to allow sharing some common behavior between a group of enumerations.
(See `OrderedEnum`_ for an example.)
Pickling
--------
Enumerations can be pickled and unpickled::
>>> from enum.test_enum import Fruit
>>> from pickle import dumps, loads
>>> Fruit.tomato is loads(dumps(Fruit.tomato, 2))
True
The usual restrictions for pickling apply: picklable enums must be defined in
the top level of a module, since unpickling requires them to be importable
from that module.
Note:
With pickle protocol version 4 (introduced in Python 3.4) it is possible
to easily pickle enums nested in other classes.
Functional API
--------------
The ``Enum`` class is callable, providing the following functional API::
>>> Animal = Enum('Animal', 'ant bee cat dog')
>>> Animal
<enum 'Animal'>
>>> Animal.ant
<Animal.ant: 1>
>>> Animal.ant.value
1
>>> list(Animal)
[<Animal.ant: 1>, <Animal.bee: 2>, <Animal.cat: 3>, <Animal.dog: 4>]
The semantics of this API resemble ``namedtuple``. The first argument
of the call to ``Enum`` is the name of the enumeration.
The second argument is the *source* of enumeration member names. It can be a
whitespace-separated string of names, a sequence of names, a sequence of
2-tuples with key/value pairs, or a mapping (e.g. dictionary) of names to
values. The last two options enable assigning arbitrary values to
enumerations; the others auto-assign increasing integers starting with 1. A
new class derived from ``Enum`` is returned. In other words, the above
assignment to ``Animal`` is equivalent to::
>>> class Animals(Enum):
... ant = 1
... bee = 2
... cat = 3
... dog = 4
Pickling enums created with the functional API can be tricky as frame stack
implementation details are used to try and figure out which module the
enumeration is being created in (e.g. it will fail if you use a utility
function in separate module, and also may not work on IronPython or Jython).
The solution is to specify the module name explicitly as follows::
>>> Animals = Enum('Animals', 'ant bee cat dog', module=__name__)
Derived Enumerations
--------------------
IntEnum
^^^^^^^
A variation of ``Enum`` is provided which is also a subclass of
``int``. Members of an ``IntEnum`` can be compared to integers;
by extension, integer enumerations of different types can also be compared
to each other::
>>> from enum import IntEnum
>>> class Shape(IntEnum):
... circle = 1
... square = 2
...
>>> class Request(IntEnum):
... post = 1
... get = 2
...
>>> Shape == 1
False
>>> Shape.circle == 1
True
>>> Shape.circle == Request.post
True
However, they still can't be compared to standard ``Enum`` enumerations::
>>> class Shape(IntEnum):
... circle = 1
... square = 2
...
>>> class Color(Enum):
... red = 1
... green = 2
...
>>> Shape.circle == Color.red
False
``IntEnum`` values behave like integers in other ways you'd expect::
>>> int(Shape.circle)
1
>>> ['a', 'b', 'c'][Shape.circle]
'b'
>>> [i for i in range(Shape.square)]
[0, 1]
For the vast majority of code, ``Enum`` is strongly recommended,
since ``IntEnum`` breaks some semantic promises of an enumeration (by
being comparable to integers, and thus by transitivity to other
unrelated enumerations). It should be used only in special cases where
there's no other choice; for example, when integer constants are
replaced with enumerations and backwards compatibility is required with code
that still expects integers.
Others
^^^^^^
While ``IntEnum`` is part of the ``enum`` module, it would be very
simple to implement independently::
class IntEnum(int, Enum):
pass
This demonstrates how similar derived enumerations can be defined; for example
a ``StrEnum`` that mixes in ``str`` instead of ``int``.
Some rules:
1. When subclassing ``Enum``, mix-in types must appear before
``Enum`` itself in the sequence of bases, as in the ``IntEnum``
example above.
2. While ``Enum`` can have members of any type, once you mix in an
additional type, all the members must have values of that type, e.g.
``int`` above. This restriction does not apply to mix-ins which only
add methods and don't specify another data type such as ``int`` or
``str``.
3. When another data type is mixed in, the ``value`` attribute is *not the
same* as the enum member itself, although it is equivalant and will compare
equal.
4. %-style formatting: ``%s`` and ``%r`` call ``Enum``'s ``__str__`` and
``__repr__`` respectively; other codes (such as ``%i`` or ``%h`` for
IntEnum) treat the enum member as its mixed-in type.
Note: Prior to Python 3.4 there is a bug in ``str``'s %-formatting: ``int``
subclasses are printed as strings and not numbers when the ``%d``, ``%i``,
or ``%u`` codes are used.
5. ``str.__format__`` (or ``format``) will use the mixed-in
type's ``__format__``. If the ``Enum``'s ``str`` or
``repr`` is desired use the ``!s`` or ``!r`` ``str`` format codes.
Decorators
----------
unique
^^^^^^
A ``class`` decorator specifically for enumerations. It searches an
enumeration's ``__members__`` gathering any aliases it finds; if any are
found ``ValueError`` is raised with the details::
>>> @unique
... class NoDupes(Enum):
... first = 'one'
... second = 'two'
... third = 'two'
Traceback (most recent call last):
...
ValueError: duplicate names found in <enum 'NoDupes'>: third -> second
Interesting examples
--------------------
While ``Enum`` and ``IntEnum`` are expected to cover the majority of
use-cases, they cannot cover them all. Here are recipes for some different
types of enumerations that can be used directly, or as examples for creating
one's own.
AutoNumber
^^^^^^^^^^
Avoids having to specify the value for each enumeration member::
>>> class AutoNumber(Enum):
... def __new__(cls):
... value = len(cls.__members__) + 1
... obj = object.__new__(cls)
... obj._value_ = value
... return obj
...
>>> class Color(AutoNumber):
... __order__ = "red green blue" # only needed in 2.x
... red = ()
... green = ()
... blue = ()
...
>>> Color.green.value == 2
True
Note:
The `__new__` method, if defined, is used during creation of the Enum
members; it is then replaced by Enum's `__new__` which is used after
class creation for lookup of existing members. Due to the way Enums are
supposed to behave, there is no way to customize Enum's `__new__`.
UniqueEnum
^^^^^^^^^^
Raises an error if a duplicate member name is found instead of creating an
alias::
>>> class UniqueEnum(Enum):
... def __init__(self, *args):
... cls = self.__class__
... if any(self.value == e.value for e in cls):
... a = self.name
... e = cls(self.value).name
... raise ValueError(
... "aliases not allowed in UniqueEnum: %r --> %r"
... % (a, e))
...
>>> class Color(UniqueEnum):
... red = 1
... green = 2
... blue = 3
... grene = 2
Traceback (most recent call last):
...
ValueError: aliases not allowed in UniqueEnum: 'grene' --> 'green'
OrderedEnum
^^^^^^^^^^^
An ordered enumeration that is not based on ``IntEnum`` and so maintains
the normal ``Enum`` invariants (such as not being comparable to other
enumerations)::
>>> class OrderedEnum(Enum):
... def __ge__(self, other):
... if self.__class__ is other.__class__:
... return self._value_ >= other._value_
... return NotImplemented
... def __gt__(self, other):
... if self.__class__ is other.__class__:
... return self._value_ > other._value_
... return NotImplemented
... def __le__(self, other):
... if self.__class__ is other.__class__:
... return self._value_ <= other._value_
... return NotImplemented
... def __lt__(self, other):
... if self.__class__ is other.__class__:
... return self._value_ < other._value_
... return NotImplemented
...
>>> class Grade(OrderedEnum):
... __ordered__ = 'A B C D F'
... A = 5
... B = 4
... C = 3
... D = 2
... F = 1
...
>>> Grade.C < Grade.A
True
Planet
^^^^^^
If ``__new__`` or ``__init__`` is defined the value of the enum member
will be passed to those methods::
>>> class Planet(Enum):
... MERCURY = (3.303e+23, 2.4397e6)
... VENUS = (4.869e+24, 6.0518e6)
... EARTH = (5.976e+24, 6.37814e6)
... MARS = (6.421e+23, 3.3972e6)
... JUPITER = (1.9e+27, 7.1492e7)
... SATURN = (5.688e+26, 6.0268e7)
... URANUS = (8.686e+25, 2.5559e7)
... NEPTUNE = (1.024e+26, 2.4746e7)
... def __init__(self, mass, radius):
... self.mass = mass # in kilograms
... self.radius = radius # in meters
... @property
... def surface_gravity(self):
... # universal gravitational constant (m3 kg-1 s-2)
... G = 6.67300E-11
... return G * self.mass / (self.radius * self.radius)
...
>>> Planet.EARTH.value
(5.976e+24, 6378140.0)
>>> Planet.EARTH.surface_gravity
9.802652743337129
How are Enums different?
------------------------
Enums have a custom metaclass that affects many aspects of both derived Enum
classes and their instances (members).
Enum Classes
^^^^^^^^^^^^
The ``EnumMeta`` metaclass is responsible for providing the
``__contains__``, ``__dir__``, ``__iter__`` and other methods that
allow one to do things with an ``Enum`` class that fail on a typical
class, such as ``list(Color)`` or ``some_var in Color``. ``EnumMeta`` is
responsible for ensuring that various other methods on the final ``Enum``
class are correct (such as ``__new__``, ``__getnewargs__``,
``__str__`` and ``__repr__``).
.. note::
``__dir__`` is not changed in the Python 2 line as it messes up some
of the decorators included in the stdlib.
Enum Members (aka instances)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The most interesting thing about Enum members is that they are singletons.
``EnumMeta`` creates them all while it is creating the ``Enum``
class itself, and then puts a custom ``__new__`` in place to ensure
that no new ones are ever instantiated by returning only the existing
member instances.
Finer Points
^^^^^^^^^^^^
``Enum`` members are instances of an ``Enum`` class, and even
though they are accessible as `EnumClass.member`, they should not be accessed
directly from the member as that lookup may fail or, worse, return something
besides the ``Enum`` member you were looking for (changed in version 1.1.1)::
>>> class FieldTypes(Enum):
... name = 1
... value = 2
... size = 3
...
>>> FieldTypes.value.size
<FieldTypes.size: 3>
>>> FieldTypes.size.value
3
Likewise, ``__members__`` is only available on the class.
In Python 3.x ``__members__`` is always an ``OrderedDict``, with the order being
the definition order. In Python 2.7 ``__members__`` is an ``OrderedDict`` if
``__order__`` was specified, and a plain ``dict`` otherwise. In all other Python
2.x versions ``__members__`` is a plain ``dict`` even if ``__order__`` was specified
as the ``OrderedDict`` type didn't exist yet.
If you give your ``Enum`` subclass extra methods, like the `Planet`_
class above, those methods will show up in a `dir` of the member,
but not of the class::
>>> dir(Planet)
['EARTH', 'JUPITER', 'MARS', 'MERCURY', 'NEPTUNE', 'SATURN', 'URANUS',
'VENUS', '__class__', '__doc__', '__members__', '__module__']
>>> dir(Planet.EARTH)
['__class__', '__doc__', '__module__', 'name', 'surface_gravity', 'value']
A ``__new__`` method will only be used for the creation of the
``Enum`` members -- after that it is replaced. This means if you wish to
change how ``Enum`` members are looked up you either have to write a
helper function or a ``classmethod``.
Platform: UNKNOWN
Classifier: Development Status :: 5 - Production/Stable
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: BSD License
Classifier: Programming Language :: Python
Classifier: Topic :: Software Development
Classifier: Programming Language :: Python :: 2.4
Classifier: Programming Language :: Python :: 2.5
Classifier: Programming Language :: Python :: 2.6
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Provides: enum
|