Python में किसी विशिष्ट Operator का मतलब या उसके बर्ताव को बदलने के लिए Operator Overloading किया जाता है |
जैसे कि, अभीतक देखा है कि '+' Operator से दो Numbers का addition, दो string का concatenate और दो sequences(list,tuple) का addition/merge देखा है , लेकिन
क्या दो class objects को '+' operator से add किया जा सकता है ? Example देखिये |
Trying to add Two Objects Without Overloading
Example पर देखे तो Operator Overloading के सिवाय दो class objects को add करने का प्रयास किया गया है | लेकिन A class के objects unsupported operands type होने के कारण 'TypeError' का exception raise होता है |
class A:
def __init__(self, a):
self.a = a
print(self.a)
obj1 = A(5)
obj2 = A(2)
print(obj1 + obj2)
Output :
5
2
print(obj1 + obj2)
TypeError: unsupported operand type(s) for +: 'A' and 'A'
अगर दो objects का addition करना हो तो Operator Overloading का इस्तेमाल करना पड़ता है |
Example for '+' Operator Overloading in Python
Operator Overloading में हर Operator के लिए अलग-अलग function का इस्तेमाल किया जाता है | जैसे कि,
निचे दिए गए example में '+' operator से दो objects को add करने के लिए '__add__()' function का इस्तेमाल किया गया है |
class A:
def __init__(self, a):
self.a = a
def disp(self):
return self.a
def __add__(self, param):
return A(self.a + param.a)
obj1 = A(5)
obj2 = A(2)
c = obj1 + obj2
print(c.disp())
Output :
7
Functions for Operator Overloading
| Operator | Function | Meaning |
|---|---|---|
| + | __add__() | Addition |
| - | __sub__() | Subtraction |
| * | __mul__() | Multiplication |
| / | __truediv__() | Division |
| % | __mod__() | Modulus |
| // | __floordiv__() | Floor Division |
| ** | __pow__() | Exponent |
| < | __lt__() | Less than |
| <= | __le__() | Less than or Equal to |
| > | __gt__() | Greater than |
| >= | __ge__() | Greater than or Equal to |
| == | __eq__() | Equal to |
| != | __ne__() | Not Equal to |
| << | __lshift__() | Left Shift |
| >> | __rshift__() | Right Shift |
| & | __and__() | Bitwise AND |
| | | __or__() | Bitwise OR |
| ^ | __xor__() | Bitwise XOR |
| ~ | __invert__() | Bitwise NOT |
| index | __getitem__(self, index) | Index |
| str | __str__() | String |
| len | __len__() | Length |
Other Example for Operator Overloading
Source Code :
class A:
def __init__(self, a):
self.a = a
def disp(self):
return self.a
def __add__(self, param):
return A(self.a + param.a)
def __sub__(self, param):
return A(self.a - param.a)
def __mul__(self, param):
return A(self.a * param.a)
def __truediv__(self, param):
return A(self.a / param.a)
def __mod__(self, param):
return A(self.a % param.a)
def __floordiv__(self, param):
return A(self.a // param.a)
def __pow__(self, param):
return A(self.a ** param.a)
def __lt__(self, param):
return A(self.a < param.a)
def __le__(self, param):
return A(self.a <= param.a)
def __gt__(self, param):
return A(self.a > param.a)
def __ge__(self, param):
return A(self.a >= param.a)
def __eq__(self, param):
return A(self.a == param.a)
def __ne__(self, param):
return A(self.a != param.a)
obj1 = A(5)
obj2 = A(2)
c = obj1 + obj2 #or obj1.__add__(obj2)
print("+ Operator = ",c.disp())
c = obj1 - obj2 #or obj1.__sub__(obj2)
print("- Operator = ",c.disp())
c = obj1 * obj2 #or obj1.__mul__(obj2)
print("* Operator = ",c.disp())
c = obj1 / obj2 #or obj1.__truediv__(obj2)
print("/ Operator = ",c.disp())
c = obj1 % obj2 #or obj1.__mod__(obj2)
print("% Operator = ",c.disp())
c = obj1 // obj2 #or obj1.__floordiv__(obj2)
print("// Operator = ",c.disp())
c = obj1 ** obj2 #or obj1.__pow__(obj2)
print("** Operator = ",c.disp())
c = obj1 < obj2 #or obj1.__lt__(obj2)
print("< Operator = ",c.disp())
c = obj1 <= obj2 #or obj1.__le__(obj2)
print("<= Operator = ",c.disp())
c = obj1 > obj2 #or obj1.__gt__(obj2)
print("> Operator = ",c.disp())
c = obj1 >= obj2 #or obj1.__ge__(obj2)
print(">= Operator = ",c.disp())
c = obj1 == obj2 #or obj1.__eq__(obj2)
print("== Operator = ",c.disp())
c = obj1 != obj2 #or obj1.__ne__(obj2)
print("!= Operator = ",c.disp())
Output :
+ Operator = 7 - Operator = 3 * Operator = 10 / Operator = 2.5 % Operator = 1 // Operator = 2 ** Operator = 25 < Operator = False <= Operator = False > Operator = True >= Operator = True == Operator = False != Operator = True