How do you check whether a python method is bound or not?

Question

Given a reference to a method, is there a way to check whether the method is bound to an object or not? Can you also access the instance that it's bound to?

Answer 1

im_self attribute

Answer 2

def isbound(method):
    return method.im_self is not None

def instance(bounded_method):
    return bounded_method.im_self

User-defined methods:

When a user-defined method object is created by retrieving a user-defined function object from a class, its im_self attribute is None and the method object is said to be unbound. When one is created by retrieving a user-defined function object from a class via one of its instances, its im_self attribute is the instance, and the method object is said to be bound. In either case, the new method's im_class attribute is the class from which the retrieval takes place, and its im_func attribute is the original function object.

In Python 2.6 and 3.0:

Instance method objects have new attributes for the object and function comprising the method; the new synonym for im_self is __self__, and im_func is also available as __func__. The old names are still supported in Python 2.6, but are gone in 3.0.