Get user-defined class attributes from class instance

Question

How to get user-defined class attributes from class instance? I tried this:

class A:
    FOO = 'foo'
    BAR = 'bar'

a = A()

print(a.__dict__)  # {}
print(vars(a))  # {}

I use python 3.5. Is there a way to get them? I know that dir(a) returns a list with names of attributes, but I need only used defined, and as a dict name to value.

score 6 · Answer 1 · edited Jun 02 '19 at 08:50

6

You've defined those variables within the class namespace which haven't propagated into instances. You can use the __class__ attribute of the instance to access the class object, and then use the __dict__ method to get the namespace's contents:

>>> {k: v for k, v in a.__class__.__dict__.items() if not k.startswith('__')}
{'BAR': 'bar', 'FOO': 'foo'}

edited Jun 02 '19 at 08:50

Pro Q

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answered Dec 07 '16 at 14:47

Mazdak

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I forget to mention that it should also return attributes from parents – danielko Dec 07 '16 at 15:15

score 1 · Answer 2 · answered Dec 07 '16 at 14:43

1

Try this:

In [5]: [x for x in dir(a) if not x.startswith('__')]
Out[5]: ['BAR', 'FOO']

answered Dec 07 '16 at 14:43

NarūnasK

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Get user-defined class attributes from class instance

2 Answers2