How can I get the parent class(es) of a Python class?
Use the following attribute:
From the docs:
The tuple of base classes of a class
>>> str.__bases__ (<type 'basestring'>,)
>>> class A(object): ... pass ... >>> class B(object): ... pass ... >>> class C(A, B): ... pass ... >>> C.__bases__ (<class '__main__.A'>, <class '__main__.B'>)
If you want all the ancestors rather than just the immediate ones, use
import inspect print inspect.getmro(cls)
Usefully, this gives you all ancestor classes in the "method resolution order" — i.e. the order in which the ancestors will be checked when resolving a method (or, actually, any other attribute — methods and other attributes live in the same namespace in Python, after all;-).
If you want to ensure they all get called, use
super at all levels.
New-style classes have an
mro method you can call which returns a list of parent classes in method resolution order.
Use bases if you just want to get the parents, use
__mro__ (as pointed out by @naught101) for getting the method resolution order (so to know in which order the init’s were executed).
Bases (and first getting the class for an existing object):
>>> some_object = "some_text" >>> some_object.__class__.__bases__ (object,)
For mro in recent Python versions:
>>> some_object = "some_text" >>> some_object.__class__.__mro__ (str, object)
Obviously, when you already have a class definition, you can just call
__mro__ on that directly:
>>> class A(): pass >>> A.__mro__ (__main__.A, object)
The fastest way to get all parents, and in order, is to just use the
import getpass getpass.GetPassWarning.__mro__
…outputs, in order:
(<class 'getpass.GetPassWarning'>, <type 'exceptions.UserWarning'>, <type 'exceptions.Warning'>, <type 'exceptions.Exception'>, <type 'exceptions.BaseException'>, <type 'object'>)
There you have it. The "best" answer may have more votes but this is so much simpler than some convoluted
for loop, looking into
__bases__ one class at a time, not to mention when a class extends two or more parent classes. Importing and using
inspect just clouds the scope unnecessarily.
This funciton will print the all the classes of an object, while in each step the next object will the left most parent.
def print_root_left(class_): while True: print(class_) # Check there if are no bases then we have reached the root class if not class_.__bases__: break class_=class_.__bases__ # use the left most parent example = "hello" print_root_left(example.__class__)
I’ve already answered this once, but you could also use "pip3 install pytis" and use/take a look at, the "getip" program, written in Python.
You may find it’s code here: https://github.com/PyTis/PyTis/blob/development/src/pytis/getip.py
I’m the author of the linked repository.
If you have a variable and want to get its class and parent classes use type() method which will give class for a variable
val="happy coding" print(type(val).__mro__)
(<class 'str'>, <class 'object'>)