Recursion:
==========

==> The function can call itself again and again until the completion of task.
That function is called as "Recursive Function"
That procedure is called as "recursion".

def fun():
	implementation

fun()

def factorial(num):
    fact = 1
    if num == 0:
        return fact
    elif num > 0:
        i = num
        while i != 0:
            fact = fact * i # 5 * 4 = 20 60 120 120
            i = i - 1   # 4 3 2 1
        return fact
    else:
        return "Factorial is not possible for negative numbers."

n = int(input("Enter an integer:"))

result = factorial(num = n)

print("The Factorial of the number",n,"is = ",result)


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

def fun():
	implementation
	fun()

# WAP TO FIND THE FACTORIAL OF THE NUMBER USING RECURSION.

def findFactorial(num):
    fact = 1
    if num == 0:
        return fact
    elif num > 0:
        return (num * findFactorial(num-1)) # 5 * 4! ==> 5 X 4 X 3! ==> 20 X 3 X 2! ==> 60 X 2 X 1! ==> 120 X 1 X 0! ==> 120 X 1 ==> 120
    else:
        return "Factorial is not possible for negative numbers."

n = int(input("Enter a positive number:"))

result = findFactorial(num = n)

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

Nested Functions:
=================
writing a function definition inside another function definition

def fun1():
	implementation
	def fun2():
		implementation

# nested function


def outer():
    print("I am the implementation of outer function.")
    def inner():
        print("I am the implementation of inner function.")
    inner()

outer()
# inner()

=================================================
How to pass a string as an argument to the function:
====================================================

def greetings(name):
    print("Good Morning",name)

name = input("Enter the name:")
greetings(name)

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

def reverseString(string):
    reverse = ""
    for i in string:
        reverse = i + reverse   # "leveL"
    return reverse

data = input("Enter the string data:")
print("The Reverse of the string = ",reverseString(data))

====================================
Passing of Collection of to the function:
=========================================

def Average(*args):
    s_total = 0
    for i in args:
        s_total += i

    avg = s_total/len(args)
    return avg

result = Average(1,2,3,4,5,6,7,8)
print(result)

# ld = (10,20,30,40,50,60)
# res1 = Average(ld)
# print(res1)

================================
def function(ld):
    even_list = []
    for i in ld:
        if i % 2 == 0:
            even_list.append(i)
    return even_list

ld = eval(input("Enter a list:"))

res_list = function(ld)
print(res_list)