如何在python中的多文件（或模块）中定义类

Question

So I want to define a Class A
looks like:

in a.py :

class A:
   def __init__(self):
       pass

   def some_method_in_a(self):
       pass

and now I want define some additional methods in b.py . looks like:

continue define class A:
def some_method_in_b_but_bellows_classA(self):
    pass

So are there any simple methods to do this?

Answer 1

I believe you would typically accomplish this using inheritance.

You define general classes which your 'A' class inherits attributes or methods from. Something like:

/b.py:

class generalObjectLikeA:
    def some_method_in_b_but_bellows_classA(self):
        pass

/a.py:

class A(b.generalObjectLikeA):
    def __init__(self):
        pass

    def some_method_in_a(self):
        pass

Answer 2

If you don't want to use inheritance for some reasons(like monkey patch), functions and classes are normal objects in python, you can change them dynamiclly.

class A(object):
    pass

a = A()

def bar(self):
    print id(self)

A.foo = bar
a.foo()
b = A()
b.foo()

References:

Monkey patch

Monkeypatching For Humans