How can I get only class variables?

Question

I have this class definition:

class cols:
    name = 'name'
    size = 'size'
    date = 'date'
    @classmethod
    def foo(cls):
        print "This is a class method"

With __dict__ I get all class attributes (members and variables). Also there are the "Internal attributes" too (like __main__). How can I get only the class variables without instantiation?

Answer 1

import inspect
inspect.getmembers(cols)

There are a lot if things you can do with the inspect module: http://lfw.org/python/inspect.html

Answer 2

I wouldn't know a straightforward way, especially since from the interpreter's POV, there is not that much of a difference between a method of a class and any other variable (methods have descriptors, but that's it...).

So when you only want non-callable class members, you have to fiddle around a little:

>>> class cols:
...     name = "name"
...     @classmethod
...     def foo(cls): pass

>>> import inspect
>>> def get_vars(cls):
...     return [name for name, obj in cls.__dict__.iteritems()
                if not name.startswith("__") and not inspect.isroutine(obj)]
>>> get_vars(cols)
['name']

Answer 3

But with inspect.getmembers I get my function foo listed too. The getmembers function have a second (optional) parameter for the type of member to be retrieved (i.e.: inspect.ismethod) but I can't find something like inspect.isattribute.

Thank you in advance.

Answer 4

Torsten you're right twice. First with your answer (you wrote the code I need) and second with your comment about my lack of comment capability (I tried to comment the coonj answer but I don't have any reputation yet).

Thank you.