diff options
| -rw-r--r-- | Doc/library/enum.rst | 9 | ||||
| -rw-r--r-- | Lib/enum.py | 16 | ||||
| -rw-r--r-- | Lib/test/test_enum.py | 66 |
3 files changed, 80 insertions, 11 deletions
diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst index 503d305..af42c58 100644 --- a/Doc/library/enum.rst +++ b/Doc/library/enum.rst @@ -400,7 +400,8 @@ 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 +enumerations; the others auto-assign increasing integers starting with 1 (use +the `start` parameter to specify a different starting value). A new class derived from :class:`Enum` is returned. In other words, the above assignment to :class:`Animal` is equivalent to:: @@ -438,12 +439,12 @@ SomeData in the global scope:: The complete signature is:: - Enum(value='NewEnumName', names=<...>, *, module='...', qualname='...', type=<mixed-in class>) + Enum(value='NewEnumName', names=<...>, *, module='...', qualname='...', type=<mixed-in class>, start=1) :value: What the new Enum class will record as its name. :names: The Enum members. This can be a whitespace or comma separated string - (values will start at 1):: + (values will start at 1 unless otherwise specified):: 'red green blue' | 'red,green,blue' | 'red, green, blue' @@ -461,6 +462,8 @@ The complete signature is:: :type: type to mix in to new Enum class. +:start: number to start counting at if only names are passed in + Derived Enumerations -------------------- diff --git a/Lib/enum.py b/Lib/enum.py index 84fa20e..b9e42ae 100644 --- a/Lib/enum.py +++ b/Lib/enum.py @@ -193,7 +193,7 @@ class EnumMeta(type): enum_class.__new__ = Enum.__new__ return enum_class - def __call__(cls, value, names=None, *, module=None, qualname=None, type=None): + def __call__(cls, value, names=None, *, module=None, qualname=None, type=None, start=1): """Either returns an existing member, or creates a new enum class. This method is used both when an enum class is given a value to match @@ -205,7 +205,7 @@ class EnumMeta(type): `value` will be the name of the new class. `names` should be either a string of white-space/comma delimited names - (values will start at 1), or an iterator/mapping of name, value pairs. + (values will start at `start`), or an iterator/mapping of name, value pairs. `module` should be set to the module this class is being created in; if it is not set, an attempt to find that module will be made, but if @@ -221,7 +221,7 @@ class EnumMeta(type): if names is None: # simple value lookup return cls.__new__(cls, value) # otherwise, functional API: we're creating a new Enum type - return cls._create_(value, names, module=module, qualname=qualname, type=type) + return cls._create_(value, names, module=module, qualname=qualname, type=type, start=start) def __contains__(cls, member): return isinstance(member, cls) and member._name_ in cls._member_map_ @@ -292,16 +292,16 @@ class EnumMeta(type): raise AttributeError('Cannot reassign members.') super().__setattr__(name, value) - def _create_(cls, class_name, names=None, *, module=None, qualname=None, type=None): + def _create_(cls, class_name, names=None, *, module=None, qualname=None, type=None, start=1): """Convenience method to create a new Enum class. `names` can be: * A string containing member names, separated either with spaces or - commas. Values are auto-numbered from 1. - * An iterable of member names. Values are auto-numbered from 1. + commas. Values are incremented by 1 from `start`. + * An iterable of member names. Values are incremented by 1 from `start`. * An iterable of (member name, value) pairs. - * A mapping of member name -> value. + * A mapping of member name -> value pairs. """ metacls = cls.__class__ @@ -312,7 +312,7 @@ class EnumMeta(type): if isinstance(names, str): names = names.replace(',', ' ').split() if isinstance(names, (tuple, list)) and isinstance(names[0], str): - names = [(e, i) for (i, e) in enumerate(names, 1)] + names = [(e, i) for (i, e) in enumerate(names, start)] # Here, names is either an iterable of (name, value) or a mapping. for item in names: diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py index f1f8063..bf9d633 100644 --- a/Lib/test/test_enum.py +++ b/Lib/test/test_enum.py @@ -634,6 +634,23 @@ class TestEnum(unittest.TestCase): self.assertIn(e, SummerMonth) self.assertIs(type(e), SummerMonth) + def test_programatic_function_string_with_start(self): + SummerMonth = Enum('SummerMonth', 'june july august', start=10) + lst = list(SummerMonth) + self.assertEqual(len(lst), len(SummerMonth)) + self.assertEqual(len(SummerMonth), 3, SummerMonth) + self.assertEqual( + [SummerMonth.june, SummerMonth.july, SummerMonth.august], + lst, + ) + for i, month in enumerate('june july august'.split(), 10): + e = SummerMonth(i) + self.assertEqual(int(e.value), i) + self.assertNotEqual(e, i) + self.assertEqual(e.name, month) + self.assertIn(e, SummerMonth) + self.assertIs(type(e), SummerMonth) + def test_programatic_function_string_list(self): SummerMonth = Enum('SummerMonth', ['june', 'july', 'august']) lst = list(SummerMonth) @@ -651,6 +668,23 @@ class TestEnum(unittest.TestCase): self.assertIn(e, SummerMonth) self.assertIs(type(e), SummerMonth) + def test_programatic_function_string_list_with_start(self): + SummerMonth = Enum('SummerMonth', ['june', 'july', 'august'], start=20) + lst = list(SummerMonth) + self.assertEqual(len(lst), len(SummerMonth)) + self.assertEqual(len(SummerMonth), 3, SummerMonth) + self.assertEqual( + [SummerMonth.june, SummerMonth.july, SummerMonth.august], + lst, + ) + for i, month in enumerate('june july august'.split(), 20): + e = SummerMonth(i) + self.assertEqual(int(e.value), i) + self.assertNotEqual(e, i) + self.assertEqual(e.name, month) + self.assertIn(e, SummerMonth) + self.assertIs(type(e), SummerMonth) + def test_programatic_function_iterable(self): SummerMonth = Enum( 'SummerMonth', @@ -707,6 +741,22 @@ class TestEnum(unittest.TestCase): self.assertIn(e, SummerMonth) self.assertIs(type(e), SummerMonth) + def test_programatic_function_type_with_start(self): + SummerMonth = Enum('SummerMonth', 'june july august', type=int, start=30) + lst = list(SummerMonth) + self.assertEqual(len(lst), len(SummerMonth)) + self.assertEqual(len(SummerMonth), 3, SummerMonth) + self.assertEqual( + [SummerMonth.june, SummerMonth.july, SummerMonth.august], + lst, + ) + for i, month in enumerate('june july august'.split(), 30): + e = SummerMonth(i) + self.assertEqual(e, i) + self.assertEqual(e.name, month) + self.assertIn(e, SummerMonth) + self.assertIs(type(e), SummerMonth) + def test_programatic_function_type_from_subclass(self): SummerMonth = IntEnum('SummerMonth', 'june july august') lst = list(SummerMonth) @@ -723,6 +773,22 @@ class TestEnum(unittest.TestCase): self.assertIn(e, SummerMonth) self.assertIs(type(e), SummerMonth) + def test_programatic_function_type_from_subclass_with_start(self): + SummerMonth = IntEnum('SummerMonth', 'june july august', start=40) + lst = list(SummerMonth) + self.assertEqual(len(lst), len(SummerMonth)) + self.assertEqual(len(SummerMonth), 3, SummerMonth) + self.assertEqual( + [SummerMonth.june, SummerMonth.july, SummerMonth.august], + lst, + ) + for i, month in enumerate('june july august'.split(), 40): + e = SummerMonth(i) + self.assertEqual(e, i) + self.assertEqual(e.name, month) + self.assertIn(e, SummerMonth) + self.assertIs(type(e), SummerMonth) + def test_subclassing(self): if isinstance(Name, Exception): raise Name |