How to find all the subclasses of a class given its name?

Question

I need a working approach of getting all classes that are inherited from a base class in Python.

Answer 1

How can I find all subclasses of a class given its name?

We can certainly easily do this given access to the object itself, yes.

Simply given its name is a poor idea, as there can be multiple classes of the same name, even defined in the same module.

I created an implementation for another answer, and since it answers this question and it's a little more elegant than the other solutions here, here it is:

def get_subclasses(cls):
    """returns all subclasses of argument, cls"""
    if issubclass(cls, type):
        subclasses = cls.__subclasses__(cls)
    else:
        subclasses = cls.__subclasses__()
    for subclass in subclasses:
        subclasses.extend(get_subclasses(subclass))
    return subclasses

Usage:

>>> import pprint
>>> list_of_classes = get_subclasses(int)
>>> pprint.pprint(list_of_classes)
[,
 ,
 ,
 ,
 ,
 ,
 ,
 ,
 ]