Python Logical Operators with Examples

Operators are used to perform operations on values and variables. These are the special symbols that carry out arithmetic and logical computations. The value the operator operates on is known as Operand.

Logical operators in Python

In Python, Logical operators are used on conditional statements (either True or False). They perform Logical AND, Logical OR and Logical NOT operations.

OPERATOR	DESCRIPTION	SYNTAX
and	Logical AND: True if both the operands are true	x and y
or	Logical OR: True if either of the operands is true	x or y
not	Logical NOT: True if operand is false	not x

The truth table for all combinations of values of X and Y.

Truth Table

Logical AND operator in Python

Logical operator returns True if both the operands are True else it returns False. Example #1:

Python3

# Python program to demonstrate
# logical and operator

a = 10
b = 10
c = -10

if a > 0 and b > 0:
    print("The numbers are greater than 0")

if a > 0 and b > 0 and c > 0:
    print("The numbers are greater than 0")
else:
    print("Atleast one number is not greater than 0")

Output

The numbers are greater than 0
Atleast one number is not greater than 0

Example #2:

Python3

# Python program to demonstrate
# logical and operator

a = 10
b = 12
c = 0

if a and b and c:
    print("All the numbers have boolean value as True")
else:
    print("Atleast one number has boolean value as False")

Output

Atleast one number has boolean value as False

Note: If the first expression evaluated to be false while using and operator, then the further expressions are not evaluated.

Logical OR operator in Python

Logical or operator returns True if either of the operands is True. Example #1:

Python3

# Python program to demonstrate
# logical or operator

a = 10
b = -10
c = 0

if a > 0 or b > 0:
    print("Either of the number is greater than 0")
else:
    print("No number is greater than 0")

if b > 0 or c > 0:
    print("Either of the number is greater than 0")
else:
    print("No number is greater than 0")

Output

Either of the number is greater than 0
No number is greater than 0

Example #2:

Python3

# Python program to demonstrate
# logical and operator

a = 10
b = 12
c = 0

if a or b or c:
    print("Atleast one number has boolean value as True")
else:
    print("All the numbers have boolean value as False")

Output

Atleast one number has boolean value as True

Note: If the first expression evaluated to be True while using or operator, then the further expressions are not evaluated.

Logical not operator in Python

Logical not operator work with the single boolean value. If the boolean value is True it returns False and vice-versa. Example:

Python3

# Python program to demonstrate
# logical not operator

a = 10

if not a:
    print("Boolean value of a is True")

if not (a%3 == 0 or a%5 == 0):
    print("10 is not divisible by either 3 or 5")
else:
    print("10 is divisible by either 3 or 5")

Output

10 is divisible by either 3 or 5

Order of Precedence of logical operators

In the case of multiple operators, Python always evaluates the expression from left to right. This can be verified by the below example. Example:

Python3

# Python program to demonstrate
# order of evaluation of logical
# operators

def order(x):
    print("Method called for value:", x)
    return True if x > 0 else False

a = order
b = order
c = order

if a(-1) or b(5) or c(10):
    print("Atleast one of the number is positive")

Output

Method called for value: -1
Method called for value: 5
Atleast one of the number is positive