Lesson #7: Operators

Python Operators are used to perform operations on values and variables. These are symbols used for the purpose of logical and arithmetic operations.

Arithmetic Operators

Arithmetic operators are used with numeric values to perform mathematical operations.

Operator	Example	Meaning
+	num_1 + num_2	Addition: adds two operands
–	num_1 – num_2	Subtraction: subtracts two operands
*	num_1 * num_2	Multiplication: multiplies two operands
/	num_1 / num_2	Division: divides the first operand by the second
%	num_1 % num_2	Modulus: returns the remainder
**	num_1 ** num_2	Exponentiation: Returns first raised to power second
//	num_1 // num_2	Floor Division: divides the first operand by the second

Example

num_1 = 20
num_2 = 10

print(num_1 + num_2)
# 30

print(num_1 – num_2)
# 10

print(num_1 * num_2)
# 200

print(num_1 / num_2)
# 2.0

print(num_1 % num_2)
# 0

print(num_1 ** num_2)
# 10240000000000

print(num_1 // num_2)
# 2

Comparison Operators

Comparison operators are used to compare two values.

Operator	Example	Meaning
==	num_1 == num_2	Equal to: returns True if both operands are equal
!=	num_1 != num_2	Not equal: returns True if operands are not equal
>	num_1 > num_2	Greater than: returns True if the num_1 is greater than the num_2
<	num_1 < num_2	Less than: returns True if the num_1 is less than the num_2
>=	num_1 >= num_2	Greater than or equal to: returns True if the num_1 is greater than or equal to the num_2
<=	num_1 <= num_2	Less than or equal to: returns True if the num_1 is less than or equal to the num_2

Example

num_1 = 20
num_2 = 10

print(num_1 == num_2)
# False

print(num_1 != num_2)
# True

print(num_1 > num_2)
# True

print(num_1 < num_2)
# False

print(num_1 >= num_2)
# True

print(num_1 <= num_2)
# False

Assignment Operators

Assignment operators are used to assign values to variables.

Operator	Example	Same as	Meaning
=	num = 2	num = 2	Assign value of right side of expression to left side operand
+=	num += 2	num = num + 2	Add
-=	num -= 2	num = num – 2	Subtract
*=	num *= 2	num = num * 2	Multiply
/=	num /= 2	num = num / 2	Divide
%=	num %= 2	num = num % 2	Modulus
//=	num //= 2	num = num // 2	Divide(floor)
**=	num **= 2	num = num ** 2	Exponent
&=	num &= 2	num = num & 2	Performs Bitwise AND on operands
\|=	num \|= 2	num = num \| 2	Performs Bitwise OR on operands
^=	num ^= 2	num = num ^ 2	Performs Bitwise xOR on operands
>>=	num >>= 2	num = num >> 2	Performs Bitwise right shift on operands
<<=	num <<= 2	num = num << 2	Performs Bitwise left shift on operands

Example

num = 0
num += 5
print(num) # 5

num = 10
num -= 5
print(num) # 5

num = 1
num *= 5
print(num) # 5

num = 5
num /= 5
print(num) # 1.0

num = 5
num %= 20
print(num) # 5

num = 100
num //= 10
print(num) # 10

num = 3
num **= 2
print(num) # 9

Identity Operators

Identity Operators are used to check if two values are located on the same part of the memory.

Operator	Example	Meaning
is	num_1 is num_2	Returns True if both variables are identical
is not	num_1 is not num_2	Returns True if both variables are not identical

Example

num_1 = 2
num_2 = 5
num_3 = num_1

print(num_1 is num_2) # False
print(num_1 is not num_2) # True
print(num_1 is num_3) # True

Logical Operators

Logical Operators are used to combine conditional statements.

Operator	Example	Meaning
and	num_1 and num_2	Logical AND: Returns True if both statements are true
or	num_1 or num_2	Logical OR: Returns True if one of the statements is true
not	num_1 not num_2	Logical NOT: Returns False if the result is true. Returns True if the result is false

Example

num_1 = 2
num_2 = 5
num_3 = 10

print(num_1 < num_2 and num_3 > num_2) # True
print(num_1 > num_2 or num_3 > num_2) # True
print(not(num_1 > num_2 or num_3 > num_2)) # False

Membership Operators

Membership Operators are used to test whether a value is in a sequence.

Operator	Example	Meaning
in	num_1 in num_2	Returns True if value is found in the sequence
not in	num_1 not in num_2	Returns True if value is not found in the sequence