In Python 3.3, PEP-3155 introduced a new __qualname__ attribut | Python etc

In Python 3.3, PEP-3155 introduced a new __qualname__ attribute for classes and functions which contains a full dotted path to the definition of the given object.

class A:
class B:
def f(self):
def g():
pass
return g

A.B.f.__name__
# 'f'

A.B.f.__qualname__
# 'A.B.f'

g = A.B().f()
g.__name__
# 'g'

g.__qualname__
# 'A.B.f..g'