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Python Programming

Operators & Operation in Python

In this , you'll learn everything about different types of operators in Python, their syntax and how to use them with examples.

Table Of Contents

Introduction

An Operator in Python are special symbol in Python that is used to perform specific mathematical or logical operation on values. In normal , we can say that it is symbols that designate that some sort of computation should be performed. The values that the operators work on are called operands.

For example :-

>>> 2+3
    5

Here in the above expression , + (plus) sign is the operator that performs addition. 2 and 3 are the operands and 5 is the output of the operation..

Python supports several kinds of operators whose categorisation is briefly explained in below section.

Types Of Operator

Python language supports the following types of operators.

Let us have a look on all operators one by one in below section .

Arithmetic Operators

Python supports arithmetic operators that are used to perform the four basic arithmetic operations as well as modular division, floor division and exponentiation.

Operator Operation Description Syntax
+ Addition Adds the two numeric values on either side of the operator
This operator can also be used to concatenate two strings on either side of the operator		 x +y
- Subtraction Subtracts the operand on the right from the operand on the left
 x - y
* Multiplication Multiplies the two values on both side of the operator
Repeats the item on left of the operator if first operand is a string and second operand is an integer value		 x * y
/ Division Divides the operand on the left by the operand on the right and returns the quotient
 x / y
% Modulus Divides the operand on the left by the operand on the right and returns the remainder
 x % y (remainder of x / y)
// Floor Division Divides the operand on the left by the operand on the right and returns the quotient by removing the decimal part. It is sometimes also called integer division
 x // y
** Exponent Performs exponential (power) calculation on operands. That is, raise the operand on the left to the power of the operand on the right
 x ** y (x to the power y)

Examples of Arithmetic Operator

  # Initialize The Value
    >>> a = 9
    >>> b = 4

  # Addition of numbers  
    >>> add = a + b  

  # Subtraction of numbers  
    >>> sub = a - b  

  # Multiplication of number  
    >>> mul = a * b  

  # Division(float) of number  
    >>> div1 = a / b  
     
  # Division(floor) of number  
    >>> div2 = a // b  

  # Modulo of both number  
    >>> mod = a % b  

   # Power 
    >>> p = a ** b 
   
    >>> print(add)  
    >>> print(sub)  
    >>> print(mul)  
    >>> print(div1)  
    >>> print(mod) 
    >>> print(div2)
    >>> print(p)

Output

      13
      5
      36
      2.25
      2
      1
      6561

Relational (Comparison) Operators

Relational operator compares the values of the operands on its either side and determines the relationship among them .

Operator Operation Description Example
== Equals to If the values of two operands are equal, then the condition is True,otherwise it is false x == y
!= Not equal to If values of two operands are not equal,then condition is True, otherwise condition is false x != y
> Greater than If the value of the left-side operand is greater than the value of the right - side operand ,then condition is true, otherwise ,it is False x > y
< Less Than If the value of the left-side operand is less than the value of the right - side operand ,then condition is true, otherwise ,it is False x < y
>= Greater than or equal to If the value of the left -side operand is less than the value of the right-side operand, then condition is true, otherwise, it is False If the value of the left-hand operand is greater than or equal to value of right-hand operator,then condition is true, otherwise it is False x >= y
<= Less than or equals to If the value of the left-hand operant is less than or equal to value of right -hand operator ,then condition is true, otherwise it is False x <= y

Example Of Relational Operator

# Initialize Value 
 >>> a = 13
 >>> b = 33

# a > b is False 
 >>> print(a > b) 

# a < b is True 
 >>> print(a < b) 

# a == b is False 
 >>> print(a == b) 

# a != b is True 
 >>> print(a != b) 

# a >= b is False 
 >>> print(a >= b) 

# a <= b is True 
 >>> print(a <= b)

Output

     False
     True
     False
     True
     False
     True

Assignment Operators

Assignment operator assigns or changes the value of the variable on its left.

Operator Description Syntax Same As
= Assign value of right side of expression to left side operand x = y + z
+= Add AND: Add right side operand with left side operand and then assign to left operand a+=b a=a+b
-= Subtract AND: Subtract right operand from left operand and then assign to left operand a-=b a=a-b
*= Multiply AND: Multiply right operand with left operand and then assign to left operand a*=b a=a*b
/= Divide AND: Divide left operand with right operand and then assign to left operand a/=b a=a/b
%= Modulus AND: Takes modulus using left and right operands and assign result to left operand a%=b a=a%b
//= Divide(floor) AND: Divide left operand with right operand and then assign the value(floor) to left operand a//=b a=a//b
**= Exponent AND: Calculate exponent(raise power) value using operands and assign value to left operand a**=b a=a**b
&= Performs Bitwise AND on operands and assign value to left operand a&=b a=a&b
|= Performs Bitwise OR on operands and assign value to left operand a=| b a=a | b
^= Performs Bitwise xOR on operands and assign value to left operand a^=b a=a^b
>>= Performs Bitwise right shift on operands and assign value to left operand a>>=b a=a>>b
<<= Performs Bitwise Left shift on operands and assign value to left operand a<<=b a=a<<b

Logical Operators

There are three logical operators supported by Python. These operators (and, or, not) are to be written in lower case only.
The logical operator evaluates to either True or False based on the logical operands on either side. Every value is logically either True or False.
By default, all values are True except None, False, 0 (zero), empty collections "", (), [], {}, and few other special values.

Operator Operations Description Example
and Logical AND If both the operands are True, then condition becomes True x < 5 and x < 10
or Logical OR If any of the two operands are True, then condition becomes True x < 5 or x < 4
not Logical NOT Used to reverse the logicalstate of its operand not(x < 5 and x < 10)

Example Of Logical Operator

     # Examples of Logical Operator 
     >>> a = True
     >>> b = False

     # Print a and b is False 
     >>> print(a and b) 

     # Print a or b is True 
     >>> print(a or b) 

     # Print not a is False 
     >>> print(not a)

Output

     False
     True
     False

Membership Operators

Membership operators are used to check if a value is a member of the given sequence or not.

Operator Description Example
in Returns true if the variable/value is found in the specified sequence and False otherwise x in y
not in Returns True if the variable/value is not found in the specified sequence and False otherwise x not in y

Example Of Membership Operator

  # Examples of Membership operator 
  >>> x = 'hello guys'
  >>> y = {3:'a',4:'b'} 


  >>> print('h' in x) 

  >>> print('Hello' not in x) 

  >>> print('hello' not in x) 

  >>> print(3 in y)

Output

  True
  True
  False
  True

Bitwise Operators

Bitwise operators treat operands as sequences of binary digits and operate on them bit by bit.
The following operators are supported:

Methods Description Example
& AND Sets each bit to 1 if both bits are 1
| OR Sets each bit to 1 if one of two bits is 1
^ XOR Sets each bit to 1 if only one of two bits is 1
~ NOT Inverts all the bits
« Zero fill left shift Shift left by pushing zeros in from the right and let the leftmost bits fall off
» Signed right shift Shift right by pushing copies of the leftmost bit in from the left, and let the rightmost bits fall off

Example Of Bitwise Operator

 # Initialize Value
 >>> a = 10
 >>> b = 4

 # Print bitwise AND operation   
 >>> print(a & b) 

 # Print bitwise OR operation 
 >>> print(a | b) 

 # Print bitwise NOT operation  
 >>> print(~a) 

 # print bitwise XOR operation  
 >>> print(a ^ b) 

 # print bitwise right shift operation  
 >>> print(a >> 2) 

 # print bitwise left shift operation  
 >>> print(a << 2)

Output

    0
   14
  -11
   14
   2
   40

Identity Operators

Identity operators are used to determine whether the value of a variable is of a certain type or not. Identity operators can also be used to determine whether two variables are referring to the same object or not. There are two identity operators.

Operator Description Example
is Evaluates True if the variables on either side of the operator point towards the same memory location and False otherwise. var1 is var2 results to True if id(var1)is equal to id(var2) x is y
is not Evaluates to False if the variables on either side of the operator point to same memory location and True otherwise. var1 is not var2 results to True if id(var1) is not equal to id(var2) x is not y

Example Of Identity Operator

 # Initializing Value 
 >>> a1 = 3
 >>> b1 = 3
 >>> a2 = 'hello'
 >>> b2 = 'hello'
 >>> a3 = [1,2,3] 
 >>> b3 = [1,2,3] 
 >>> print(a1 is not b1) 


 >>> print(a2 is b2) 

# Output is False, since lists are mutable. 
 >>> print(a3 is b3)

Output

     False
     True
     False

Precedence of Operators

Evaluation of the expression is based on precedence of operators. When an expression contains different kinds of operators, precedence determines which operator should be applied first.
Higher precedence operator is evaluated before the lower precedence operator. Most of the operators studied till now are binary operators. Binary operators are operators with two operands. The unary operators need only one operand, and they have a higher precedence than the binary operators. The minus (-) as well as + (plus) operators can act as both unary and binary operators, but not is a unary logical operator.

# Depth is using - (minus) as unary operator
Value = -Depth
# not is a unary operator, negates True
print(not(True))

The following table lists precedence of all operators from highest to lowest :-

Order of precedence Operators Description
1 ** Exponentiation(raised to the power
2 -,+,- Complement, unary plus and unary minus
3 *,/,%,// Multiply,divide,modulo and floor division
4 +,- Addition and Subtraction
5 <=,<,>,>= Relational Operators
6 ==,!= Equality operators
7 =,%=,/=,//=,-=, =,+= Assignment operators
8 is, is not Identity operators
9 in,not in Membership operators
10 not,or,and Logical operators

Note :-

  • Parenthesis can be used to override the precedence of operators. The expression within () is evaluated first.
  • For operators with equal precedence, the expression is evaluated from left to right.

How will Python evaluate the following expression?

20 + 30 * 40

Solution:
= 20 + (30 * 40) #Step 1
precedence of * is more than that of +
= 20 + 1200 #Step 2
= 1220 #Step 3

How will the following expression be evaluated in Python?

15.0 / 4 + (8 + 3.0)

Solution:
= 15.0 / 4 + (8.0 + 3.0) #Step 1
= 15.0 / 4.0 + 11.0 #Step 2
= 3.75 + 11.0 #Step 3
= 14.75 #Step 4

Any All in Python

Any and All are two built ins provided in python used for successive And/Or. Let Us Discuss It One By One :-

Any

Returns true if any of the items is True. It returns False if empty or all are false. Any can be thought of as a sequence of OR operations on the provided iterables. It short circuit the execution i.e. stop the execution as soon as the result is known.

Syntax :-

 any(list of iterables)

Example

 # Since all are false, false is returned 
 >>> print (any([False, False, False, False])) 

 # Here the method will short-circuit at the 
 # second item (True) and will return True. 
 >>> print (any([False, True, False, False])) 

 # Here the method will short-circuit at the 
 # first (True) and will return True. 
 >>> print (any([True, False, False, False]))

Output

 False
 True
 True

All

Returns true if all of the items are True (or if the iterable is empty). All can be thought of as a sequence of AND operations on the provided iterables. It also short circuit the execution i.e. stop the execution as soon as the result is known.

Syntax :-

 all(list of iterables)

Example

# Here all the iterables are True so all 
# will return True and the same will be printed 
 >>> print (all([True, True, True, True])) 

# Here the method will short-circuit at the  
# first item (False) and will return False. 
 >>> print (all([False, True, True, False])) 

# This statement will return False, as no 
# True is found in the iterables 
 >>> print (all([False, False, False]))

Output

 True
 False
 False

Conclusion

In this, you learned about the diverse operators that Python supports to combine objects into expressions.