How do I test if int value exists in Python Enum without using try/catch?

test for values

variant 1

note that an Enum has a member called _value2member_map_ (which is undocumented and may be changed/removed in future python versions):

print(Fruit._value2member_map_)# {4: <Fruit.Apple: 4>, 5: <Fruit.Orange: 5>, 6: <Fruit.Pear: 6>}

you can test if a value is in your Enum against this map:

5 in Fruit._value2member_map_  # True7 in Fruit._value2member_map_  # False

variant 2

if you do not want to rely on this feature this is an alternative:

values = [item.value for item in Fruit]  # [4, 5, 6]

or (probably better): use a set; the in operator will be more efficient:

values = set(item.value for item in Fruit)  # {4, 5, 6}

then test with

5 in values  # True7 in values  # False

add has_value to your class

you could then add this as a method to your class:

class Fruit(Enum):    Apple = 4    Orange = 5    Pear = 6    @classmethod    def has_value(cls, value):        return value in cls._value2member_map_ print(Fruit.has_value(5))  # Trueprint(Fruit.has_value(7))  # False

test for keys

if you want to test for the names (and not the values) i would use _member_names_:

'Apple' in Fruit._member_names_  # True'Mango' in Fruit._member_names_  # False

You could use Enum.__members__ - an ordered dictionary mapping names to members:

In [12]: 'Apple' in Fruit.__members__Out[12]: TrueIn [13]: 'Grape' in Fruit.__members__Out[13]: False

There is a way to have all the enums be able to check if an item is present:

import enum class MyEnumMeta(enum.EnumMeta):     def __contains__(cls, item):         return item in [v.value for v in cls.__members__.values()] class MyEnum(enum.Enum, metaclass=MyEnumMeta):    FOO = "foo"    BAR = "bar"

Now you can do an easy check:

>>> "foo" in MyEnumTrue

It can even be made simpler if all the enum's values will always be the same type -- for example strings:

import enum  class MyEnumMeta(enum.EnumMeta):      def __contains__(cls, item):         return item in cls.__members__.values()class MyEnum(str, enum.Enum, metaclass=MyEnumMeta):     FOO = "foo"     BAR = "bar"

Edit: Yet another version, technically the most correct one:

import enum class MyEnumMeta(enum.EnumMeta):     def __contains__(cls, item):         try:            cls(item)        except ValueError:            return False        else:            return Trueclass MyEnum(enum.Enum, metaclass=MyEnumMeta):    FOO = "foo"    BAR = "bar"