Operators

Operators are special symbols which help the user to carry out arithmetic operations like addition, subtraction, etc. and logical operations like comparison, xor, not etc between operands.

The built-in operator module¹ exports a set of functions corresponding to the intrinsic operators of Python. The operator module becomes particularly valuable when you need to pass an operation as an argument to another function, or when aiming for a more functional programming style.

Classification

The operators fall into categories that perform object comparisons, logical operations, mathematical operations and sequence operations.

• Arithmetic Operators
• Assignment Operators
• Comparison Operators
• Logical Operators
• Bitwise Operators
• Special Operators

Arithmetic Operators

Arithmetic operators are used to perform mathematical operations as listed in the table.

>>> a = 10
>>> b = 3
>>>
>>> # Addition operator : +
>>> a + b
>>> 13
>>>
>>> # Subtraction operator : -
>>> a - b
>>> 7
>>>
>>> # Multiplication operator : *
>>> a * b
>>> 30
>>>
>>> # Division operator : /
>>> a / b
>>> 3.3333333333333335
>>>
>>> # Floor division operator : // (Quotient)
>>> a // b
>>> 3
>>>
>>> # Modulus operator : % (Remainder)
>>> a % b    
>>> 1
>>>
>>> # Exponent operator : **
>>> a ** b
>>> 1000
>>>

>>> import numpy as np
>>> matrix_1 = np.array( [ [1, 2], [3, 4] ] )
>>> matrix_2 = np.array( [ [5, 6], [7, 8] ] )
>>> 
>>> matrix_1
array([[1, 2],
       [3, 4]])
>>> matrix_2
array([[5, 6],
       [7, 8]])
>>> 
>>> # Matrix multiplication operator @
>>> matrix_1 @ matrix_2
array([[19, 22],
       [43, 50]])

>>> course = "Python "
>>> tag = "Advanced"
>>> course + tag
Python Advanced

>>> positive_numbers = [1, 3, 5 , 7, 9]
>>> negative_numbers = [-9, -7, -5, -3, -1, ]
>>> negative_numbers + positive_numbers
[-9, -7, -5, -3, -1, 1, 3, 5, 7, 9]

Assignment Operators

Equal to = sign is used as an assignment operator in python to assign value to a variable. To simplify code and reduce redundancy, python includes arithmetic assignment and bitwise assignment operators.

>>> a = 5
>>> b = 2
>>> 
>>> # a = a + 3 can be written as a += 3
>>> a += 3 
>>> a
8
>>>
>>> # b = b * 2 can be written as b *= 2
>>> b *= 2
>>> b
4
>>> # similarly for other operators.

Comparison Operators

Comparison of relational operators compares the values. It either returns True or False according to the condition.

>>> a = 5
>>> b = 2
>>> 
>>> a == b 
False
>>>
>>> a != b
True
>>> a > b 
True
>>>
>>> a < b
False
>>>
>>> a >= b
True
>>>
>>> a <= b
False

Logical Operators

Logical operators are used to check whether an expression is True or False. They are used in decision-making.

temperature = 30
office = "Open"

# AND logic used to check if both the conditions are TRUE
# any one of the condition is false, AND login output will be False
if (set_temperature > 23 ) and (office == "Open"):
    print("Turn On the FAN 𖣘༄")
else:
    print("Turn Off the FAN 𖣘")

>>> a = True
>>> b = False
>>> 
>>> a and b
False
>>>
>>> a or b
True
>>>
>>> not a
False
>>>

Bitwise Operator

In Python, bitwise operators are used to performing bitwise calculations on integers. The integers are first converted into binary (BASE 2) and then operations are performed on each bit or corresponding pair of bits, hence the name bitwise operators. The result is then returned in decimal (BASE 10) format.

>>> a = 10  # decimal 10 is equivalent to 1010 (Binary)  
>>> b = 4   # decimal 4 is equivalent to 0100 (Binary)
>>>
>>> a & b  # 0b1010 & 0b0100 = 0b0000  (0)
0
>>> a | b  # 0b1010 | 0b0100 = 0b1110  (14)
14 

Special Operators

Python language offers some special types of operators like the identity operator and the membership operator.

Identity Operators

is and is not are the identity operators both are used to check if two values are located on the same part of the memory. Two variables that are equal do not imply that they are identical.

• is : True if the operands are identical
• is not : True if the operands are not identical

>>> a = 10
>>> c = 10
>>>
>>> a is c
True
>>>
>>> even = [2, 4, 6, 8]
>>> number = [2, 4, 6, 8]
>>>
>>> even is number
False
>>> even[0] is number[0]
True
>>>

Membership Operators

in and not in are the membership operators; used to test whether a value or variable is in a sequence.

• in : True if value is found in the sequence
• not in : True if value is not found in the sequence

>>> name = "Aavishkarah"
>>> 'A' in name
True
>>>
>>> 'z' in name
False
>>>
>>> 'z' not in name
True
>>>