I have an enum that I define like this:
def make_enum(**enums):
return type('Enum', (), enums)
an_enum = make_enum(first=1, second=2)
At some later point I would like to check, if a value that I took as a parameter in a funciton is part of an_enum. Usually i would do it like this
assert 1 in to_list(an_enum)
How can I convert the enum object an_enum to a list? If that is not possible, how can I check if a value "is part of the enum"?
Python's Enum object has build-in enumerable.name and enumerable.value attributes for each member of an Enum.
an_enum = Enum('AnEnum', {'first': 1, 'second': 2})
[el.value for el in an_enum]
# returns: [1, 2]
[el.name for el in an_enum]
# returns: ['first', 'second']
Sidenode: Be careful with assert. If someone runs your script with python -O asserts will never fail.
To check if a value is part of an enum:
if 1 in [el.value for el in an_enum]:
pass
How can I convert the enum object an_enum to a list?
>>> [name for name in dir(an_enum) if not name.startswith('_')]
['first', 'second']
How can I check if a value "is part of the enum"?
>>> getattr(an_enum, 'first')
1
>>> getattr(an_enum, '1')
Traceback [...]
AttributeError: type object 'Enum' has no attribute '1'
[getattr(an_enum, name) for name in dir(an_enum) if not name.startswith('_')] and you will get what I need [1, 2]
I'm not sure why you're defining enums like you do, there's supported functional way to do this:
en_enum = Enum('Numbers', {'first': 1, 'second': 2})
If this suits your needs, you can do
>>> en_enum(1)
<Numbers.first: 1>
>>> en_enum(3)
ValueError: 3 is not a valid Numbers
not actually membership check, but you don't need any special methods/transformers
[getattr(an_enum, name) for name in dir(an_enum) if not name.startswith('_')], but this way of writing enums is a lot nicer for sure. Also I did not know that you can simply get the enums elements by doing an_enum(x). So thanks!
type(an_enum)to get the class?Enumtype that supportslist(an_enum)plus much more.