Initialization of Multiple Inheritance in Python

Question

I came across the following python code in which a class inherits from two parent classes. I am trying to understand the constructor of the class.

# wrapper.py:
#############
class EWrapper:
    def __init__(self):
        pass

...

# client.py
###########
class EClient(object):
    def __init__(self, wrapper):
        self.msg_queue = queue.Queue()
        self.wrapper = wrapper
        self.decoder = None
        self.reset()
....

# Test.py
#########
class TestApp(EWrapper, EClient):
    def __init__(self):
        EClient.__init__(self, self)

Could someone kindly shed more light on EClient.__init__(self, self)? It's not clear to me the usage of two selfs. How does python know which self is which?

What is the process of constructing an object of TestApp?

Can you clarify your question? What do you mean by "How does python know which self is which?"? There is only one object bound to all self names. The name self works like all other variable names. — MisterMiyagi
– MisterMiyagi, Commented Apr 17, 2020 at 5:27
On a general note, the naming of classes implies that Wrapper should contain a Client, not be a Client. Composition may be more appropriate than inheritance here. — MisterMiyagi
– MisterMiyagi, Commented Apr 17, 2020 at 5:49

bipll · Accepted Answer · 2020-04-17 05:59:58Z

2

In the call EClient.__init__(self, self) the first self becomes that of EClient in EClient's def __init__(self, wrapper):. Next, as you may see, the second self gets bound to wrapper in that call. TestApp inherits EWrapper so it uses itself as a wrapper for EClient.

answered Apr 17, 2020 at 5:59

bipll

12k1 gold badge21 silver badges32 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Luck Box · Accepted Answer · 2020-04-17 05:21:06Z

1

When initializing TestApp you are using the self of the EWrapper and then EClient since that is the order defined in the class.

answered Apr 17, 2020 at 5:21

Luck Box

902 silver badges15 bronze badges

Collectives™ on Stack Overflow

Initialization of Multiple Inheritance in Python

2 Answers 2

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Related