Nested Functions in python

Nested Methods:

• Defining a method inside another method.
• We cannot access nested method from outside.

def outer():
    print("outer method")

    def inner():
        print("inner method")
        return
    return

outer()
inner() # error

We access nested method from the definition of outer() method.

def outer():
    print("outer method")

    def inner():
        print("inner method")
        return

    inner()
    return

outer()

Local and Non local variables in nested methods:

• Local variables are defined inside the inner function.
• Outer function variables are called non local variables of inner function.
• When we access a variable inside the nested function, it gives the priority to nested function only.

def outer():
    x=10
    print("outer x : ",x)

    def inner():
        x=20
        print("inner x : ",x)
        return

    inner()
    return

outer()

Non variables are nothing but, accessing outer() method variables inside inner() method when local variable is not present inside inner method.

def outer():
    x=10
    print("outer x : ",x)

    def inner():
        print("inner x : ",x)
        return

    inner()
    return

outer()

• Arguments are working like local variables of function.
• Outer() method arguments working like non local variables of nested method.

def outer(x):
    print("outer x : ",x)

    def inner():
        print("inner x : ",x)
        return

    inner()
    return

outer(50)