How to check whether a variable is a class or not?

Question

I was wondering how to check whether a variable is a class (not an instance!) or not.

I\'ve tried to use the function isinstance(object, class_or_type_or_tuple

Answer 1

>>> class X(object):
...     pass
... 
>>> type(X)
<type 'type'>
>>> isinstance(X,type)
True

Answer 2

Benjamin Peterson is correct about the use of inspect.isclass() for this job. But note that you can test if a Class object is a specific Class, and therefore implicitly a Class, using the built-in function issubclass. Depending on your use-case this can be more pythonic.

from typing import Type, Any
def isclass(cl: Type[Any]):
    try:
        return issubclass(cl, cl)
    except TypeError:
        return False

Can then be used like this:

>>> class X():
...     pass
... 
>>> isclass(X)
True
>>> isclass(X())
False

Answer 3

isinstance(X, type)

Return True if X is class and False if not.