Python Examples

Example Python Code

class Numbers(object):
    ONE = 1
    TWO = 2
    THREE = 3
 
assert Numbers.ONE == 1
assert Numbers.TWO == 2
assert Numbers.THREE == 3

def enum(**enums):
    return type('Enum', (object,), enums)
 
Numbers = enum(ONE=1, TWO=2, THREE=3)
 
assert Numbers.ONE == 1
assert Numbers.TWO == 2
assert Numbers.THREE == 3

class Enum(set):
    def __getattr__(self, name):
        if name in self:
            return name
        raise AttributeError
 
Numbers = Enum( "ONE TWO THREE".split() )
 
error = False
try:
    print Numbers.ONE
    print Numbers.TWO
    print Numbers.THREE
except:
    error = True
assert error == False
 
try:
    print Numbers.FOUR
except:
    error = True
assert error == True

5 Responses to “How to create an enum in Python?”

1. Cameron Hayne says:

   June 4, 2011 at 11:29 am

   I used method #2 (a function that dynamically creates a new class) but in a more elaborate way that satisfies the several requirements I had for enums that were to be part of an API.
   See my blog post: http://franktheblue.blogspot.com/2011/05/enums-in-python-more-flexible-and.html

   Reply
2. admin says:

   June 5, 2011 at 12:25 am

   Thanks Cameron. Nice post!

   Reply
3. Carlo Pires says:

   September 5, 2011 at 9:35 pm

   As of python 2.6 enums can be created using namedtuples. See http://bit.ly/qBJTpq

   Reply
4. admin says:

   September 24, 2011 at 2:28 am

   Thanks Carlo

   Reply
5. Genffe says:

   December 3, 2012 at 4:56 pm

   thanks for your source code.

   Reply