CODEWITHSUNDEEP
python
Djaff
Djaff

Reputation: 183

I don't understand the order of methods in python

I don't understand why the code uses the print_me method from Class D, and not the method in class A.

I did some testing using print-statements and can see that it reads the print_me-method of class D before initialising class A, but I don't understand why it doesn't do the same for class A. 

class A:
    name = "Alfa"

    def __init__(self, foo):
        self.foo = foo
        foo = 100
        self.print_me()

    def print_me(self):
        print(self.name, self.foo)

class B(A):
    name = "Beta"

    def __init__(self, bar = 40):
        self.bar = bar
        print(self.name, bar)

class C:
    name = "Charlie"

class D(A, C):
    name = "Delta"

    def __init__(self, val):
        A.__init__(self, val)

    def print_me(self):
        print(self.name, "says", self.foo)

d = D(60)

The output is: Delta says 60

I thought it would be: Delta 60

Upvotes: 0

Views: 110

Answers (1)

blue note
blue note

Reputation: 29089

Because the self you are passing to the __init__ of A is still an instance of D, not A. And the function A.__init__ is calling self.print_me, which belongs to D.

If you do a = A(); a.print_me() you'd get what you expect.

Important note: The __init__ method in python is not the actual constructor, it is just a method that is automatically called after the actual construction of the object. However, when you call it yourself, it works just like any other method.

Upvotes: 3

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