Polymorphism:
=============
poly ==> many
morphs ==> ways

one thing in multiple ways
one form with multiple definitions is called as "poly morphism".

# overriding:
=============
def fun(a,b):
	return a+b

def fun(a, b, c):
	return a*b*c

# overloading
==============
def f1(a,b):
	return a+b

def f1(a,b,c):
	return a+b+c

ex: x-bank:
	def personal_loan():
		roi = 0%
	def home_loan():
		roi = 0%
	def car_loan():
		roi = 0%

icici = x-bank()

icici.personal_loan():
	roi = 10%

==> polymorphism can be implemented in two ways:
	1) Overloading
		operator overloading	
		method overloading
		constructor overloading
	2) Overriding
		method overriding
		constructor overriding

operator overloading
====================
a = 10
b = 20
c = a + b	# 30	addition
d = a * b	# 200	multiplication

s1 = "a"
s2 = "b"

s3 = s1 + s2 	# "ab"	concatenation/joining
s4 = s1 * 3	# "aaa"	repetition of string

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

# Operator Overloading

# + operator can be overloaded?

# + = numbers (addition) or string (concatenation)

# + = object?

class Book:
    def __init__(self,pages):
        self.pages = pages

    def __add__(self, other):
        return self.pages + other.pages

    def __sub__(self, other):
        return self.pages - other.pages

    def __mul__(self, other):
        return self.pages * other.pages

    def __lt__(self, other):
        return self.pages < other.pages

b1 = Book(100)
b2 = Book(200)

# print(b1 + b2)  # Type Error (when + operator was not overloaded)
print("The Total number of pages in a book = ",b1 + b2)
print(b2 - b1)
print(b1 * b2)

print(b1 < b2)

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

+ ==> __add__(self,other)
- ==> __sub__(self,other)
* ==> __mul__(self, other)
/ ==> __div__(self, other)
// ==> __floordiv__(self, other)
% ==> __mod__(self, other)
** ==> __pow__(self, other)
+= ==> __iadd__(self, other)
-= ==> __isub__(self, other)
*= ==> __imul__(self, other)
/= ==> __idiv__(self, other)
//= ==> __ifloordiv__(self, other)
%= ==> __imod__(self, other)
**= ==> __ipow__(self, other)
< ==> __lt__(self, other)
<= ==> __le__(self, other)
> ==> __gt__(self, other)
>= ==> __ge__(self, other)
== ==> __eq__(self, other)
!= ==> __ne__(self, other)

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

# WAP TO OVERLOAD MULTIPLICATION OPERATOR TO WORK ON EMPLOYEE OBJET

class Employee:
    def __init__(self,name, salary):
        self.name = name
        self.salary = salary

    def __mul__(self, other):
        return self.salary * other.days

class timeSheet:
    def __init__(self,name,days):
        self.name = name
        self.days = days

e = Employee('Arjun',4500)
t = timeSheet('Arjun',30)

print("The Arjun's salary of the september month = ",e * t)

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

Method Overloading:
===================

# method overloading

# fun() ==> sum on 0, 1, 2, 10, 100, 200

class Calculator:
    def sum(self,a = None,b = None,c = None):
        if a != None and b != None and c != None:
            print("The Sum of Three numbers = ",a+b+c)
        elif a != None and b != None:
            print("The Sum of Two Numbers = ",a+b)
        elif a!=None:
            print("The Sum of one number = ",a)
        else:
            print("Kindly provide at least one argument for proceeding.")

calsi = Calculator()
calsi.sum()
calsi.sum(100)
calsi.sum(100,200)
calsi.sum(100,200,300)
# calsi.sum(100,200,300,400)

========================================
# method overloading


class Calculator:
    def sum(self,*n):
        total = 0

        for i in n:
            total += i
        return total

cal = Calculator()
print("The Sum = ",cal.sum())   # 0 parameters
print("The sum = ",cal.sum(100))    # 1 parameter
print("The Sum = ",cal.sum(100,300,500))    # 3
print("The Sum = ",cal.sum(100,200,300,400,500))    # 5

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

Constructor Overloading:
========================
Python does not support the constructor Overloading.

# Constructor Overloading

class myClass:
    def __init__(self):
        print("Hi")

    def __init__(self,name):
        print("Hi",name)

mc = myClass("Ravi")