Python_developement/python advance/python-MRO.py at main · ashutosh-engineer/Python_developement · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
class A:
    def show(self):
        print("A")

class B(A):
    pass

B().show()
print(B.__mro__)
# (<class '__main__.B'>, <class '__main__.A'>, <class 'object'>)


# c3 Linearization Algorithm
#Used By python to find classes
'''
Child class alwasy comes before the Parrent class
Then parrent class and then class attributes
'''


class A:
    pass

class B(A):
    pass

class C(B):
    pass

print(C.__mro__)

'''

(<class '__main__.C'>, <class '__main__.B'>, <class '__main__.A'>, <class 'object'>)
'''


class A:
    def greet(self):
        print("Hello from A")

class B(A):
    def greet(self):
        print("Hello from A")
        super().greet()

class C(A):
    def greet(self):
        print("Hello from A")
        super().greet()

class D(B, C):
    pass

D().greet()
# Now kiska Greet pehle chlega
# <D, B, C , A , object>


# Now understanding how super method
# Calls according to rules of MRO


print(D.__mro__)

# Debugging MRO
# Whenever there is a bug in complex inheritance
#Use __mro__ or mro() to check

# Super is next in MRo not direct parrent Method