Python
Python Operators
Operators are the constructs which can manipulate the value of operands.
Python supports following operators.
  • Arithmetic Operators
  • Comparison Operators
  • Logical Operators
  • Assignment Operators
  • Bitwise Operator
  • Conditional Operators

Arithmetic Operators

Arithmetic operators are used to perform mathematical operations like addition, subtraction, multiplication etc.

Operator Meaning Example
+ Add two operands or unary plus x + y
- Subtract right operand from the left or unary minus x - y
* Multiply two operands x * y
/ Divide left operand by the right one (always results into float) x / y
% Modulus - remainder of the division of left operand by the right x % y (remainder of x/y)
// Floor division - division that results into whole number adjusted to the left in the number line x // y
** Exponent - left operand raised to the power of right x**y (x to the power y)
Example :
>>> x = 25
>>> y = 14
>>> print('x + y =',x+y)
x + y = 39
>>> print('x - y =',x-y)
x - y = 11
>>> print('x * y =',x*y)
x * y = 350
>>> print('x / y =',x/y)
x / y = 1.7857142857142858
>>> print('x // y =',x//y)
x // y = 1
>>> print('x ** y =',x**y)
x ** y = 37252902984619140625
>>> 

Comparison Operators

These operators compare the values on either sides of them and decide the relation among them. They are also called Relational operators.

Operator Description Example
== If the values of two operands are equal, then the condition becomes true. (a == b) is not true.
!= If values of two operands are not equal, then condition becomes true.
> If the value of left operand is greater than the value of right operand, then condition becomes true. (a > b) is not true.
< If the value of left operand is less than the value of right operand, then condition becomes true. (a < b) is true.
>= If the value of left operand is greater than or equal to the value of right operand, then condition becomes true. (a >= b) is not true.
<= If the value of left operand is less than or equal to the value of right operand, then condition becomes true. (a <= b) is true.
Example :
>>> x = 15
>>> y = 20
>>> print('x > y  is',x>y)
x > y  is False
>>> print('x < y  is',x<y)
x < y  is True
>>> print('x == y is',x==y)
x == y is False
>>> print('x != y is',x!=y)
x != y is True
>>> print('x >= y is',x>=y)
x >= y is False
>>> print('x <= y is',x<=y)
x <= y is True
>>> 

Logical Operators

Logical operators are the and, or, not operators.

Operator Example Result
and (x and y) is True if both x and y are true.
or (x or y) is True if either x or y is true.
not (x not y) If a condition is true then Logical not operator will make false.
Example :
>>> x = True
>>> y = False
>>> print('x and y is',x and y)
x and y is False
>>> print('x or y is',x or y)
x or y is True
>>> print('not x is',not x)
not x is False
>>> 

Assignment Operators

Python assignment operators are used for assigning the value of the right operand to the left operand. Various assignment operators used in Python are (+=, - = , *=, /= , etc.)

Operator Shorthand Expression Description
+= x+=y x = x + y Adds 2 numbers and assigns the result to left operand.
-= x-= y x = x -y Subtracts 2 numbers and assigns the result to left operand.
*= x*= y x = x*y Multiplies 2 numbers and assigns the result to left operand.
/= x/= y x = x/y Divides 2 numbers and assigns the result to left operand.
%= x%= y x = x%y Computes the modulus of 2 numbers and assigns the result to left operand.
**= x**=y x = x**y Performs exponential (power) calculation on operators and assign value to the equivalent to left operand.
//= x//=y x = x//y Performs floor division on operators and assign value to the left operand.
Example :
>>> x = 12
>>> y = 7
>>> x+=y
>>> print(x)
19
>>> x-=y
>>> print(x)
12
>>> x*=y
>>> print(x)
84
>>> x/=y
>>> print(x)
12.0
>>> x%=y
>>> print(x)
5.0
>>> x**=y
>>> print(x)
78125.0
>>> x//=y
>>> print(x)
11160.0
>>> 

Bitwise Operators

Bitwise operators act on operands as if they were string of binary digits. It operates bit by bit, hence the name.

Operator Shorthand Expression Description
& And x & y Bits that are set in both x and y are set.
| Or x | y Bits that are set in either x or y are set.
^ Xor x ^ y Bits that are set in x or y but not both are set.
~ Not ~x Bits that are set in x are not set, and vice versa.
<< Shift left x <<y Shift the bits of x, y steps to the left
>> Shift right x >>y Shift the bits of x, y steps to the right.
Example :
>>> x = 10
>>> y = 7
>>> print(x&y)
2
>>> print (x|y)
15
>>> print (~x)
-11
>>> print (x^y)
13
>>> print (x>>2)
2
>>> print (x<<2)
40
>>> 

Membership Operators

Python’s membership operators test for membership in a sequence, such as strings, lists, or tuples. There are two membership operators as explained below

Operator Description Example
in Evaluates to true if it finds a variable in the specified sequence and false otherwise. x in y, here in results in a 1 if x is a member of sequence y.
not in Evaluates to true if it does not finds a variable in the specified sequence and false otherwise. x not in y, here not in results in a 1 if x is not a member of sequence y.
Example :
>>> x = 'Hello world'
>>> y = {1:'a',2:'b'}
>>> print('H' in x)
True
>>> print('hello' not in x)
True
>>> print(1 in y)
True
>>> print('a' in y)
False
>>> 

Identity Operators

Identity operators compare the memory locations of two objects. There are two Identity operators explained below :

Operator Description Example
is Evaluates to true if the variables on either side of the operator point to the same object and false otherwise. x is y, here is results in 1 if id(x) equals id(y).
is not Evaluates to false if the variables on either side of the operator point to the same object and true otherwise. x is not y, here is not results in 1 if id(x) is not equal to id(y).
Example :
>>> x1 = 9
>>> y1 = 9
>>> x2 = 'FTL'
>>> y2 = 'FTL'
>>> x3 = [1,2,3,4,5]
>>> y3 = [1,2,3,4,5]
>>> print(x1 is not y1)
False
>>> print(x2 is y2)
True
>>> print(x3 is y3)
False
>>>