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authorKumar Aditya <59607654+kumaraditya303@users.noreply.github.com>2022-01-17 15:18:13 (GMT)
committerGitHub <noreply@github.com>2022-01-17 15:18:13 (GMT)
commit83d544b9292870eb44f6fca37df0aa351c4ef83a (patch)
treeea79ba5ffd709ae98958ad245b92983cc51c29e5 /Doc/library/enum.rst
parent16901c0482734dbd389b09ca3edfcf3e22faeed7 (diff)
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bpo-40066: [Enum] skip failing doc test (GH-30637)
Diffstat (limited to 'Doc/library/enum.rst')
-rw-r--r--Doc/library/enum.rst265
1 files changed, 173 insertions, 92 deletions
diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst
index 8bb19dc..a37c9d4 100644
--- a/Doc/library/enum.rst
+++ b/Doc/library/enum.rst
@@ -31,7 +31,7 @@ An enumeration:
* uses *call* syntax to return members by value
* uses *index* syntax to return members by name
-Enumerations are created either by using the :keyword:`class` syntax, or by
+Enumerations are created either by using :keyword:`class` syntax, or by
using function-call syntax::
>>> from enum import Enum
@@ -45,7 +45,7 @@ using function-call syntax::
>>> # functional syntax
>>> Color = Enum('Color', ['RED', 'GREEN', 'BLUE'])
-Even though we can use the :keyword:`class` syntax to create Enums, Enums
+Even though we can use :keyword:`class` syntax to create Enums, Enums
are not normal Python classes. See
:ref:`How are Enums different? <enum-class-differences>` for more details.
@@ -53,7 +53,7 @@ are not normal Python classes. See
- The class :class:`Color` is an *enumeration* (or *enum*)
- The attributes :attr:`Color.RED`, :attr:`Color.GREEN`, etc., are
- *enumeration members* (or *enum members*) and are functionally constants.
+ *enumeration members* (or *members*) and are functionally constants.
- The enum members have *names* and *values* (the name of
:attr:`Color.RED` is ``RED``, the value of :attr:`Color.BLUE` is
``3``, etc.)
@@ -110,15 +110,10 @@ Module Contents
:class:`StrEnum` defaults to the lower-cased version of the member name,
while other Enums default to 1 and increase from there.
- :func:`global_enum`
-
- :class:`Enum` class decorator to apply the appropriate global `__repr__`,
- and export its members into the global name space.
-
- :func:`.property`
+ :func:`property`
Allows :class:`Enum` members to have attributes without conflicting with
- other members' names.
+ member names.
:func:`unique`
@@ -131,7 +126,7 @@ Module Contents
.. versionadded:: 3.6 ``Flag``, ``IntFlag``, ``auto``
-.. versionadded:: 3.11 ``StrEnum``, ``EnumCheck``, ``FlagBoundary``
+.. versionadded:: 3.11 ``StrEnum``, ``EnumCheck``, ``FlagBoundary``, ``property``
---------------
@@ -145,6 +140,11 @@ Data Types
to subclass *EnumType* -- see :ref:`Subclassing EnumType <enumtype-examples>`
for details.
+ *EnumType* is responsible for setting the correct :meth:`__repr__`,
+ :meth:`__str__`, :meth:`__format__`, and :meth:`__reduce__` methods on the
+ final *enum*, as well as creating the enum members, properly handling
+ duplicates, providing iteration over the enum class, etc.
+
.. method:: EnumType.__contains__(cls, member)
Returns ``True`` if member belongs to the ``cls``::
@@ -162,32 +162,31 @@ Data Types
.. method:: EnumType.__dir__(cls)
Returns ``['__class__', '__doc__', '__members__', '__module__']`` and the
- names of the members in ``cls``. User-defined methods and methods from
- mixin classes will also be included::
+ names of the members in *cls*::
>>> dir(Color)
- ['BLUE', 'GREEN', 'RED', '__class__', '__doc__', '__members__', '__module__']
+ ['BLUE', 'GREEN', 'RED', '__class__', '__contains__', '__doc__', '__getitem__', '__init_subclass__', '__iter__', '__len__', '__members__', '__module__', '__name__', '__qualname__']
.. method:: EnumType.__getattr__(cls, name)
Returns the Enum member in *cls* matching *name*, or raises an :exc:`AttributeError`::
>>> Color.GREEN
- Color.GREEN
+ <Color.GREEN: 2>
.. method:: EnumType.__getitem__(cls, name)
- Returns the Enum member in *cls* matching *name*, or raises a :exc:`KeyError`::
+ Returns the Enum member in *cls* matching *name*, or raises an :exc:`KeyError`::
>>> Color['BLUE']
- Color.BLUE
+ <Color.BLUE: 3>
.. method:: EnumType.__iter__(cls)
Returns each member in *cls* in definition order::
>>> list(Color)
- [Color.RED, Color.GREEN, Color.BLUE]
+ [<Color.RED: 1>, <Color.GREEN: 2>, <Color.BLUE: 3>]
.. method:: EnumType.__len__(cls)
@@ -201,7 +200,7 @@ Data Types
Returns each member in *cls* in reverse definition order::
>>> list(reversed(Color))
- [Color.BLUE, Color.GREEN, Color.RED]
+ [<Color.BLUE: 3>, <Color.GREEN: 2>, <Color.RED: 1>]
.. class:: Enum
@@ -232,7 +231,7 @@ Data Types
.. attribute:: Enum._ignore_
``_ignore_`` is only used during creation and is removed from the
- enumeration once that is complete.
+ enumeration once creation is complete.
``_ignore_`` is a list of names that will not become members, and whose
names will also be removed from the completed enumeration. See
@@ -261,7 +260,7 @@ Data Types
.. method:: Enum.__dir__(self)
Returns ``['__class__', '__doc__', '__module__', 'name', 'value']`` and
- any public methods defined on ``self.__class__`` or a mixin class::
+ any public methods defined on *self.__class__*::
>>> from datetime import date
>>> class Weekday(Enum):
@@ -276,7 +275,7 @@ Data Types
... def today(cls):
... print('today is %s' % cls(date.today().isoweekday()).name)
>>> dir(Weekday.SATURDAY)
- ['__class__', '__doc__', '__module__', 'name', 'today', 'value']
+ ['__class__', '__doc__', '__eq__', '__hash__', '__module__', 'name', 'today', 'value']
.. method:: Enum._generate_next_value_(name, start, count, last_values)
@@ -298,6 +297,11 @@ Data Types
>>> PowersOfThree.SECOND.value
6
+ .. method:: Enum.__init_subclass__(cls, \**kwds)
+
+ A *classmethod* that is used to further configure subsequent subclasses.
+ By default, does nothing.
+
.. method:: Enum._missing_(cls, value)
A *classmethod* for looking up values not found in *cls*. By default it
@@ -317,42 +321,55 @@ Data Types
>>> Build.DEBUG.value
'debug'
>>> Build('deBUG')
- Build.DEBUG
+ <Build.DEBUG: 'debug'>
.. method:: Enum.__repr__(self)
Returns the string used for *repr()* calls. By default, returns the
- *Enum* name and the member name, but can be overridden::
+ *Enum* name, member name, and value, but can be overridden::
- >>> class OldStyle(Enum):
- ... RETRO = auto()
- ... OLD_SCHOOl = auto()
- ... YESTERYEAR = auto()
+ >>> class OtherStyle(Enum):
+ ... ALTERNATE = auto()
+ ... OTHER = auto()
+ ... SOMETHING_ELSE = auto()
... def __repr__(self):
... cls_name = self.__class__.__name__
- ... return f'<{cls_name}.{self.name}: {self.value}>'
- >>> OldStyle.RETRO
- <OldStyle.RETRO: 1>
+ ... return f'{cls_name}.{self.name}'
+ >>> OtherStyle.ALTERNATE, str(OtherStyle.ALTERNATE), f"{OtherStyle.ALTERNATE}"
+ (OtherStyle.ALTERNATE, 'OtherStyle.ALTERNATE', 'OtherStyle.ALTERNATE')
.. method:: Enum.__str__(self)
Returns the string used for *str()* calls. By default, returns the
- member name, but can be overridden::
+ *Enum* name and member name, but can be overridden::
- >>> class OldStyle(Enum):
- ... RETRO = auto()
- ... OLD_SCHOOl = auto()
- ... YESTERYEAR = auto()
+ >>> class OtherStyle(Enum):
+ ... ALTERNATE = auto()
+ ... OTHER = auto()
+ ... SOMETHING_ELSE = auto()
... def __str__(self):
- ... cls_name = self.__class__.__name__
- ... return f'{cls_name}.{self.name}'
- >>> OldStyle.RETRO
- OldStyle.RETRO
+ ... return f'{self.name}'
+ >>> OtherStyle.ALTERNATE, str(OtherStyle.ALTERNATE), f"{OtherStyle.ALTERNATE}"
+ (<OtherStyle.ALTERNATE: 1>, 'ALTERNATE', 'ALTERNATE')
+
+ .. method:: Enum.__format__(self)
+
+ Returns the string used for *format()* and *f-string* calls. By default,
+ returns :meth:`__str__` returns, but can be overridden::
+
+ >>> class OtherStyle(Enum):
+ ... ALTERNATE = auto()
+ ... OTHER = auto()
+ ... SOMETHING_ELSE = auto()
+ ... def __format__(self, spec):
+ ... return f'{self.name}'
+ >>> OtherStyle.ALTERNATE, str(OtherStyle.ALTERNATE), f"{OtherStyle.ALTERNATE}"
+ (<OtherStyle.ALTERNATE: 1>, 'OtherStyle.ALTERNATE', 'ALTERNATE')
-.. note::
+ .. note::
- Using :class:`auto` with :class:`Enum` results in integers of increasing value,
- starting with ``1``.
+ Using :class:`auto` with :class:`Enum` results in integers of increasing value,
+ starting with ``1``.
.. class:: IntEnum
@@ -367,7 +384,7 @@ Data Types
... TWO = 2
... THREE = 3
>>> Numbers.THREE
- Numbers.THREE
+ <Numbers.THREE: 3>
>>> Numbers.ONE + Numbers.TWO
3
>>> Numbers.THREE + 5
@@ -375,10 +392,14 @@ Data Types
>>> Numbers.THREE == 3
True
-.. note::
+ .. note::
- Using :class:`auto` with :class:`IntEnum` results in integers of increasing value,
- starting with ``1``.
+ Using :class:`auto` with :class:`IntEnum` results in integers of increasing
+ value, starting with ``1``.
+
+ .. versionchanged:: 3.11 :meth:`__str__` is now :func:`int.__str__` to
+ better support the *replacement of existing constants* use-case.
+ :meth:`__format__` was already :func:`int.__format__` for that same reason.
.. class:: StrEnum
@@ -392,13 +413,16 @@ Data Types
instead of ``isinstance(str, unknown)``), and in those locations you
will need to use ``str(StrEnum.member)``.
+ .. note::
-.. note::
+ Using :class:`auto` with :class:`StrEnum` results in the lower-cased member
+ name as the value.
- Using :class:`auto` with :class:`StrEnum` results in values of the member name,
- lower-cased.
+ .. note:: :meth:`__str__` is :func:`str.__str__` to better support the
+ *replacement of existing constants* use-case. :meth:`__format__` is likewise
+ :func:`int.__format__` for that same reason.
-.. versionadded:: 3.11
+ .. versionadded:: 3.11
.. class:: Flag
@@ -431,9 +455,9 @@ Data Types
Returns all contained members::
>>> list(Color.RED)
- [Color.RED]
+ [<Color.RED: 1>]
>>> list(purple)
- [Color.RED, Color.BLUE]
+ [<Color.RED: 1>, <Color.BLUE: 4>]
.. method:: __len__(self):
@@ -461,42 +485,52 @@ Data Types
Returns current flag binary or'ed with other::
>>> Color.RED | Color.GREEN
- Color.RED|Color.GREEN
+ <Color.RED|GREEN: 3>
.. method:: __and__(self, other)
Returns current flag binary and'ed with other::
>>> purple & white
- Color.RED|Color.BLUE
+ <Color.RED|BLUE: 5>
>>> purple & Color.GREEN
- 0x0
+ <Color: 0>
.. method:: __xor__(self, other)
Returns current flag binary xor'ed with other::
>>> purple ^ white
- Color.GREEN
+ <Color.GREEN: 2>
>>> purple ^ Color.GREEN
- Color.RED|Color.GREEN|Color.BLUE
+ <Color.RED|GREEN|BLUE: 7>
.. method:: __invert__(self):
Returns all the flags in *type(self)* that are not in self::
>>> ~white
- 0x0
+ <Color: 0>
>>> ~purple
- Color.GREEN
+ <Color.GREEN: 2>
>>> ~Color.RED
- Color.GREEN|Color.BLUE
+ <Color.GREEN|BLUE: 6>
+
+ .. method:: _numeric_repr_
+
+ Function used to format any remaining unnamed numeric values. Default is
+ the value's repr; common choices are :func:`hex` and :func:`oct`.
+
+ .. note::
-.. note::
+ Using :class:`auto` with :class:`Flag` results in integers that are powers
+ of two, starting with ``1``.
- Using :class:`auto` with :class:`Flag` results in integers that are powers
- of two, starting with ``1``.
+ .. versionchanged:: 3.11 The *repr()* of zero-valued flags has changed. It
+ is now::
+ >>> Color(0) # doctest: +SKIP
+ <Color: 0>
.. class:: IntFlag
@@ -509,9 +543,9 @@ Data Types
... GREEN = auto()
... BLUE = auto()
>>> Color.RED & 2
- 0x0
+ <Color: 0>
>>> Color.RED | 2
- Color.RED|Color.GREEN
+ <Color.RED|GREEN: 3>
If any integer operation is performed with an *IntFlag* member, the result is
not an *IntFlag*::
@@ -524,15 +558,25 @@ Data Types
* the result is a valid *IntFlag*: an *IntFlag* is returned
* the result is not a valid *IntFlag*: the result depends on the *FlagBoundary* setting
-.. note::
+ The *repr()* of unnamed zero-valued flags has changed. It is now:
+
+ >>> Color(0)
+ <Color: 0>
+
+ .. note::
+
+ Using :class:`auto` with :class:`IntFlag` results in integers that are powers
+ of two, starting with ``1``.
+
+ .. versionchanged:: 3.11 :meth:`__str__` is now :func:`int.__str__` to
+ better support the *replacement of existing constants* use-case.
+ :meth:`__format__` was already :func:`int.__format__` for that same reason.
- Using :class:`auto` with :class:`IntFlag` results in integers that are powers
- of two, starting with ``1``.
.. class:: EnumCheck
*EnumCheck* contains the options used by the :func:`verify` decorator to ensure
- various constraints; failed constraints result in a :exc:`TypeError`.
+ various constraints; failed constraints result in a :exc:`ValueError`.
.. attribute:: UNIQUE
@@ -582,11 +626,11 @@ Data Types
...
ValueError: invalid Flag 'Color': aliases WHITE and NEON are missing combined values of 0x18 [use enum.show_flag_values(value) for details]
-.. note::
+ .. note::
- CONTINUOUS and NAMED_FLAGS are designed to work with integer-valued members.
+ CONTINUOUS and NAMED_FLAGS are designed to work with integer-valued members.
-.. versionadded:: 3.11
+ .. versionadded:: 3.11
.. class:: FlagBoundary
@@ -606,7 +650,7 @@ Data Types
>>> StrictFlag(2**2 + 2**4)
Traceback (most recent call last):
...
- ValueError: StrictFlag: invalid value: 20
+ ValueError: <flag 'StrictFlag'> invalid value 20
given 0b0 10100
allowed 0b0 00111
@@ -621,7 +665,7 @@ Data Types
... GREEN = auto()
... BLUE = auto()
>>> ConformFlag(2**2 + 2**4)
- ConformFlag.BLUE
+ <ConformFlag.BLUE: 4>
.. attribute:: EJECT
@@ -647,12 +691,52 @@ Data Types
... GREEN = auto()
... BLUE = auto()
>>> KeepFlag(2**2 + 2**4)
- KeepFlag.BLUE|0x10
+ <KeepFlag.BLUE|16: 20>
.. versionadded:: 3.11
---------------
+Supported ``__dunder__`` names
+""""""""""""""""""""""""""""""
+
+:attr:`__members__` is a read-only ordered mapping of ``member_name``:``member``
+items. It is only available on the class.
+
+:meth:`__new__`, if specified, must create and return the enum members; it is
+also a very good idea to set the member's :attr:`_value_` appropriately. Once
+all the members are created it is no longer used.
+
+
+Supported ``_sunder_`` names
+""""""""""""""""""""""""""""
+
+- ``_name_`` -- name of the member
+- ``_value_`` -- value of the member; can be set / modified in ``__new__``
+
+- ``_missing_`` -- a lookup function used when a value is not found; may be
+ overridden
+- ``_ignore_`` -- a list of names, either as a :class:`list` or a :class:`str`,
+ that will not be transformed into members, and will be removed from the final
+ class
+- ``_order_`` -- used in Python 2/3 code to ensure member order is consistent
+ (class attribute, removed during class creation)
+- ``_generate_next_value_`` -- used to get an appropriate value for an enum
+ member; may be overridden
+
+ .. note::
+
+ For standard :class:`Enum` classes the next value chosen is the last value seen
+ incremented by one.
+
+ For :class:`Flag` classes the next value chosen will be the next highest
+ power-of-two, regardless of the last value seen.
+
+.. versionadded:: 3.6 ``_missing_``, ``_order_``, ``_generate_next_value_``
+.. versionadded:: 3.7 ``_ignore_``
+
+---------------
+
Utilities and Decorators
------------------------
@@ -668,15 +752,6 @@ Utilities and Decorators
``_generate_next_value_`` can be overridden to customize the values used by
*auto*.
-.. decorator:: global_enum
-
- A :keyword:`class` decorator specifically for enumerations. It replaces the
- :meth:`__repr__` method with one that shows *module_name*.*member_name*. It
- also injects the members, and their aliases, into the global namespace they
- were defined in.
-
-.. versionadded:: 3.11
-
.. decorator:: property
A decorator similar to the built-in *property*, but specifically for
@@ -688,7 +763,7 @@ Utilities and Decorators
*Enum* class, and *Enum* subclasses can define members with the
names ``value`` and ``name``.
-.. versionadded:: 3.11
+ .. versionadded:: 3.11
.. decorator:: unique
@@ -714,7 +789,7 @@ Utilities and Decorators
:class:`EnumCheck` are used to specify which constraints should be checked
on the decorated enumeration.
-.. versionadded:: 3.11
+ .. versionadded:: 3.11
---------------
@@ -726,14 +801,20 @@ Notes
These three enum types are designed to be drop-in replacements for existing
integer- and string-based values; as such, they have extra limitations:
- - ``format()`` will use the value of the enum member, unless ``__str__``
- has been overridden
+ - ``__str__`` uses the value and not the name of the enum member
- - ``StrEnum.__str__`` uses the value and not the name of the enum member
+ - ``__format__``, because it uses ``__str__``, will also use the value of
+ the enum member instead of its name
- If you do not need/want those limitations, you can create your own base
- class by mixing in the ``int`` or ``str`` type yourself::
+ If you do not need/want those limitations, you can either create your own
+ base class by mixing in the ``int`` or ``str`` type yourself::
>>> from enum import Enum
>>> class MyIntEnum(int, Enum):
... pass
+
+ or you can reassign the appropriate :meth:`str`, etc., in your enum::
+
+ >>> from enum import IntEnum
+ >>> class MyIntEnum(IntEnum):
+ ... __str__ = IntEnum.__str__