NOTES
If no base class is defined for a class, then it is a subclass of “object“.
So, not defining base class is equivalent to – class MyClass(object)
NOTES
If a method implementation in the base class servers our purpose, and sufficient for our requirement, then we do not need to reimplement it in a subclass.
Inherit from Single Class
class BigBoxParent:
def myParentMethOne(self):
print("my Parent Meth One")
def myParentMethTwo(self):
print("my Parent Meth Two")
class BigBoxChild(BigBoxParent):
def myChildMethodOne(self):
print("My Child Method One")
child_obj = BigBoxChild()
child_obj.myChildMethodOne()
child_obj.myParentMethOne()
print(dir(child_obj))Output:
My Child Method One
my Parent Meth One
['__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__',
'__getattribute__', '__getstate__', '__gt__', '__hash__', '__init__', '__init_subclass__',
'__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__',
'__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__',
'myChildMethodOne', 'myParentMethOne', 'myParentMethTwo']Inherit from Multiple Classes
class BigBoxParent:
def myParentMethOne(self):
print("my Parent Method One")
def myParentMethTwo(self):
print("my Parent Method Two")
class NewParent:
def newParentMethOne(self):
print("new Parent Method one")
def newParentMethTwo(self):
print("new Parent Method Two")
class BigBoxChild(BigBoxParent, NewParent):
def myChildMethodOne(self):
print("My Child Method One")
child_obj = BigBoxChild()
child_obj.myChildMethodOne()
child_obj.myParentMethOne()
child_obj.newParentMethTwo()
print(dir(child_obj))Output:
My Child Method One
my Parent Method One
new Parent Method Two
['__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__',
'__ge__', '__getattribute__', '__getstate__', '__gt__', '__hash__', '__init__',
'__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__',
'__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__',
'__weakref__', 'myChildMethodOne', 'myParentMethOne', 'myParentMethTwo',
'newParentMethOne', 'newParentMethTwo']__init__ Execution in Inheritance
class BigBoxParent:
def __init__(self):
print("BigBoxParent __init__")
def myParentMethOne(self):
print("my Parent Method One")
def myParentMethTwo(self):
print("my Parent Method Two")
class NewParent:
def __init__(self):
print("NewParent __init__")
def newParentMethOne(self):
print("new Parent Method one")
def newParentMethTwo(self):
print("new Parent Method Two")
class BigBoxChild(BigBoxParent, NewParent):
def __init__(self):
super().__init__()
print("BigBoxChild __init__")
def myChildMethodOne(self):
print("My Child Method One")
child_obj = BigBoxChild()
child_obj.myChildMethodOne()
child_obj.myParentMethOne()
child_obj.newParentMethTwo()
Output:
BigBoxParent __init__
BigBoxChild __init__
My Child Method One
my Parent Method One
new Parent Method TwoParent __init__ Execution
class BigBoxParent:
def __init__(self):
print("BigBoxParent __init__")
def myParentMethOne(self):
print("my Parent Method One")
def myParentMethTwo(self):
print("my Parent Method Two")
class NewParent:
def __init__(self):
print("NewParent __init__")
def newParentMethOne(self):
print("new Parent Method one")
def newParentMethTwo(self):
print("new Parent Method Two")
class BigBoxChild(BigBoxParent, NewParent):
def __init__(self):
NewParent()
print("BigBoxChild __init__")
def myChildMethodOne(self):
print("My Child Method One")
child_obj = BigBoxChild()
child_obj.myChildMethodOne()
child_obj.myParentMethOne()
child_obj.newParentMethTwo()
Output:
NewParent __init__
BigBoxChild __init__
My Child Method One
my Parent Method One
new Parent Method Two