CODEWITHSUNDEEP
pythoninheritancesuper
Pranay Saraiwala
Pranay Saraiwala

Reputation: 43

call a base class method using a derived class object outside the derived class

i have seen many posts that describe how to call base class function is called inside a derived class function using the super keyword.I want to call a base class overloaded function globally using a derived class object.

class a:
    def __init__(self):
        self.x=45
    def fun(self):
        print "fun in base class"
class b(a):
    def __init__(self):
        self.y=98           
    def fun(self):
        print "fun in derived class"
objb=b()
objb.fun()#here i want to call the base class fun()

Upvotes: 0

Views: 2780

Answers (2)

Archeo
Archeo

Reputation: 221

Input:

objb = b()
super(b, objb).fun()

Output:

fun in base class

Edit:

As mentionned in comment below, in Python 2.7+ you need to declare class a(object) for this to work. This comes from a historical evolution of classes in Python, with this solution being functional for "new-style" classes only, i.e. for classes inheriting from object. In Python 3.x however, all classes are "new-style" by default, meaning you don't have to perform this small addition.

Upvotes: 1

zwer
zwer

Reputation: 25769

If you really want to call the 'base' function that works on old-style classes (classes that don't extend object) you can do it like:

objb = b()
a.fun(objb)  # fun in base class

Or if you don't know the base/parent class, you can 'extract' it from the instance itself:

objb = b()
objb.__class__.__bases__[0].fun(objb)  # fun in base class

But save yourself some trouble and just extend your base classes from object so you can use the super() notation instead of doing bases acrobatics.

Upvotes: 1

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