Operators

What are Python Operators

Operators are symbols that perform operations on operands. Operands can be variables, strings, numbers, booleans etc

Table of Contents

• What are Python Operators
• Arithmetic
• Assignment
• Comparison
• The BMI Example
• Identity
• Logical
• Membership
• Exercise

Arithmetic

Arithemators are symbols that perform mathematical operations on operands

Addition Operator

The addition operator returns the sum of its numerical operands

# Addition
x = 10 
y = 5

summation = x + y
print(summation)

15

It can also be used to concatenate or join strings together

first_name = 'Juma '
last_name = 'Shafara'

full_name = first_name + last_name
print(full_name)

Juma Shafara

Subtraction Operator

The subtraction operator returns the difference of its numerical operands

# Subraction
x = 10 
y = 5

difference = x - y
print(difference)

5

Multiplication Operator

The multiplication operator returns the product of its numerical operands

# Multiplication
x = 10 
y = 5

product = x * y
print(product)

50

Division Operator

The division operator returns the quotient of its numerical operands.

# Division
x = 10 
y = 5

quotient = x / y
print(quotient)

2.0

Exponentiation Operator

The exponentiation operator raises the left operand to the power of the right operand

# Exponentiation
x = 10 
y = 5

exponent = x ** y
print(exponent)

100000

Remainder Operators

The remainder operator, also knows as the modulus operator returns the remainder after dividing the left operand by the right operand

# Remainder
x = 10 
y = 5

remainder = x % y
print(remainder)

0

Floor Division Operator

The floor division rounds down the quotient of its numerical operands to the nearest whole number.

# Floor Division
x = 10 
y = 5

floor = 10 // 4
print(floor)

2

Operator Sequence

Operator sequence describes the order of performed operations in an arithmetic expression.

answer = 10 * 3 / 2 + 1
print(answer)

16.0

Assignment

Assignment operators are used to assign values to variables.

Assignment

The assignment operator assigns a value to a variable

# Assignment
number = 10
print(number)

10

Addition Assignment

The addition assignment operator adds the left and right operands and assigns the sum to the left operand (the variable)

# Addition Ass
x += 5 # x = x + 5 => x = 10 + 5 => x = 15
print(x)

15

Subtraction Assignment

The subtraction assignment operators deducts the right operand and assigns the difference to the left operand (the variable)

# Subraction Ass
x = 10
x -= 5 # x = x - 5 => x = 10 - 5 => x = 5
print(x)

5

Comparison

A comparison operator compares its operands and returns a Boolean value based on whether the comparison is True of False

Equality

The equality operator compares two values and returns True if the operands are equal, otherwise returns False

# Equality 
print('Voila' == 'Viola') # False
print(5 == 5) # True

False
True

Inequality

The inequality operator compares two values and returns True if the operands are Not equal, otherwise returns False

# Inequality 
print('Voila' != 'Viola')
print(10 != 10)

True
False

Greater than

The greater than operator returns True if the left operand is greater than the right operand, otherwise returns False.

print(8 > 4) # True
print(5 > 10) # False

True
False

Less than

The less than operator returns True if the left operand is less than the right operand, otherwise returns False

print(10 < 15) # True
print(20 < 10) # False

True
False

Greater than or equal to

The greater than or equal to operator returns True if the left operand is greater than or equal to the right operand, otherwise returns False

# Greater or Equal
34 >= 43

False

Less than or equal to

The less than or equal to operator returns True if the left operand is less than or equal to the right operand, otherwise returns False

print(10 <= 15) # True
print(10 <= 10) # True
print(20 <= 10) # False

True
True
False

The Body Mass Index Example

In this example, we use the operators to calculate the body mass index of a person.

weight = 56
height = 1.5

bmi = weight / (height**2)

print('BMI: ', bmi)

BMI:  24.88888888888889

Identity

Identity operators are used to compare two values to determine if they point to the same object

The is operator

This operator returns True if both operands point to the same object.

# Example 1
x = 5
y = 4

print(x is y)

False

# Example 2
x = 5 
y = 4
z = x

print(x is y) # False
print(x is z) # True

False
True

The is not operator

This operator return True if both operands do Not point to the same object in memory

# Example
# is
x = 5
y = 4
z = x 

print(x is not y) # True
print(x is not z) # False

True
False

Logical

Logical operators are commonly used with Booleans. In Python, there are 3 logical operators

Logical and

The logical and operator returns True if both operands are True

# Example
# Logical and
x = 4
print(x > 3 and 8 < x)
#               True and False => False

False

Logical or

The logical or operator returns True if one of the operands is True

# Logical or
y = 7
expression_2 = 10 > y or 4 > y
#                   True or False => True
print(expression_2)

True

Logical not

The logical not operator returns True if the operand is False, otherwise returns False if the operand is True

# Logical not
z = 8
expression_3 = not(10 == z)
#               not False => True
print(expression_3)

True

Membership

Membership operators are used to check if a sequence is present in an object like a string, list etc

The in operator

The in operator returns True if a sequence or value is present in an object

# Example
name = 'Tinye Robert'
print('Robert' in name)

True

The not in operator

The not in operator returns True if a sequence or value is NOT present in an object

# Example
name = 'Tinye Robert'
print('Robert' not in name)

False

Exercise

A car increases it velocity from u ms-1 to v ms-1 within t seconds. Write a program to calculate the acceleration.

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