meta without __metaclass__ (by inheritance)

m.py

from __future__ import print_function
from functools import wraps


class Fish(object):
    def __new__(cls, *args, **kwargs):
        o = super(Fish, cls).__new__(cls, *args, **kwargs)
        o.foo_cache = {}
        o.type = 'goldfish'

        for name, val in vars(cls).items():
            if name.startswith('foo_') and callable(val):
                setattr(o, name, Fish.cache_foo_deco(val, o))

        return o

    def extra(self):
        print("*" * 15)

    def clear_foo_cache(self):
        self.extra()
        print("Clearing cache")
        self.extra()
        self.foo_cache.clear()

    @staticmethod
    def cache_foo_deco(func, o):
        @wraps(func)
        def wrapper(*args, **kwargs):
            if func.__name__ not in o.foo_cache:
                o.foo_cache[func.__name__] = func(o, *args, **kwargs)
            return o.foo_cache[func.__name__]
        return wrapper



class Cat(Fish):
    def __init__(self):
        if not hasattr(self, 'type'):
            self.type = 'pussycat'

    def iam(self):
        print('I am a', self.type)

    def foo_name(self):
        print("processing lola")
        return "lola"

    def foo_type(self):
        print("processing ani")
        return "ani"



def main():
    """
    >> main()
    ***************
    I am a goldfish
    ***************
    processing lola
    lola
    lola
    lola
    ***************
    processing ani
    ani
    ani
    ani
    ***************
    Clearing cache
    ***************
    processing lola
    lola
    lola
    lola
    ***************
    processing ani
    ani
    ani
    ani
    """
    cat = Cat()

    cat.extra()
    Cat().iam()
    cat.extra()

    print(cat.foo_name())
    print(cat.foo_name())
    print(cat.foo_name())
    cat.extra()
    print(cat.foo_type())
    print(cat.foo_type())
    print(cat.foo_type())

    cat.clear_foo_cache()

    print(cat.foo_name())
    print(cat.foo_name())
    print(cat.foo_name())
    cat.extra()
    print(cat.foo_type())
    print(cat.foo_type())
    print(cat.foo_type())

if __name__ == '__main__':
    main()