Python Cookbook

Getting All Members of a Class Hierarchy

Credit: Jürgen Hermann, Alex Martelli

Problem

You need to map all members of a class, including inherited members, into a dictionary of class attribute names.

Solution

Here is a solution that works portably and transparently on both new-style (Python 2.2) and classic classes with any Python version:

def all_members(aClass):
    try:
        # Try getting all relevant classes in method-resolution order
        mro = list(aClass._ _mro_ _)
    except AttributeError:
        # If a class has no _ _mro_ _, then it's a classic class
        def getmro(aClass, recurse):
            mro = [aClass]
            for base in aClass._ _bases_ _: mro.extend(recurse(base, recurse))
            return mro
        mro = getmro(aClass, getmro)
    mro.reverse(  )
    members = {}
    for someClass in mro: members.update(vars(someClass))
    return members

Discussion

The all_members function in this recipe creates a dictionary that includes each member (such as methods and data attributes) of a class with the name as the key and the class attribute value as the corresponding value. Here’s a usage example:

class Eggs:
    eggs = 'eggs'
    spam = None

class Spam:
    spam = 'spam'

class Breakfast(Spam, Eggs):
    eggs = 'scrambled'

print all_members(Eggs)
print all_members(Spam)
print all_members(Breakfast)

And here’s the output of this example (note that the order in which each dictionary’s items are printed is arbitrary and may vary between Python interpreters):

{'spam': None, '_ _doc_ _': None, 'eggs': 'eggs', '_ _module_ _': '_ _main_ _'}
{'spam': 'spam', '_ _doc_ _': None, ...