Closures:
=========
what is closure?
================
==> a nested function
Syntax:
	def outer_function():
		implementation
		def inner_function():
			implementation
==> has access a variable from an enclosing function that has finished its execution.
==> That variable not bound in the local scope.
==> If the variable is immutable type:
	we can use "nonlocal" keyword to modify that immutable variable.

Advantage:
==========
1) can avoid the usage of global variable
2) provide some form of the data hiding.

Nested Function:
================

def fun1(): # Outer function
    print("This is the Outer function")
    def fun2(): # Inner Function
        print("This is the Inner function")
    print("Hi")
    print("Good Morning")
    print("This is Python Advanced Class")
    fun2()

fun1()

==========================================
Variable Scope:
===============

def outerFunction(x): # x = 1122
    y = 1221
    def innerFunction(z): # z = 1234
        return x + y + z
    return innerFunction

returningFunction = outerFunction(1122) # function aliasing returningFunction = innerFunction

result = returningFunction(1234)

print(result)

=================================
def outer(name):
    # name = local valriable to the "outer" function
    name = "Ashok IT"
    def inner():
        print("Name = ",name)
    return inner

res1 = outer("Python") # function aliasing 
res1()

=======================================================

Non-local:
=========

def f1():
    a = 112 # Immutable 
    def f2():
        nonlocal a
        b = 121
        a = a + b
        return a
    return f2

r1 = f1()
print(r1())

print(r1())

print(r1())

print(r1())