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Comparison Operators

Comparison operators are used to compare the values of two objects. For example, you might want to compare

  • is a equal to b: a == b

  • is a not equal to b: a != b

  • is a greater than b: a > b

  • is a less than b: a < b

  • is a greater than or equal to b: a >= b

  • is a less than or equal to b: a <= b

== operator

First we will learn how to check if two things are equal in Python. To do this we use the operator ==. When comparing two objects with ==, it will return True if the two values are equal otherwise it will return False. Here are some examples. Notice that the return type of each expression is a Boolean data type (True or False).

1 == 1 

True

1 == 2

False

'hello world' == 'hello world'

True

'Hello world' == 'hello world' # not the same string because capital H on the left

False

a = 'string'
b = 10
a == b

False

a = 5
b = 6
c = 3
d = 14

print(a + b)
print(d - c)
print(a + b == d - c)

11
11
True

str1 = "a b c d e f"[::2] # from index 0 to end with a stride of 2
print(str1)

str2 = "a  b  c  d  e  f"[0::3] # from index 0 to end with a stride of 3
print(str1)

# str1 and str1 are the same value
str1 == str2

abcdef
abcdef

True

True == False # they are not equal so returns False

False

True == True

True

False == False

True

!= operator

The operator != checks if two things are not equal. It returns True if they are not equal and False otherwise.

1 != 1

False

True != False

True

True != True

False

False != False

False

str(40) + str(40) != 4040

True

str(40) + str(40) != '4040'

False

40 + 40 != 80

False

40 + 40 != '80'

True

3.14 != 6.28 / 2

False

> operator

This is the greater than operator: >. It returns True if the value on the left is greater than the value on the right. Otherwise it returns False.

2 > 1 # yes, 2 is greater than 1

True

1 > 2 # no, 1 is not greater than 2

False

2 > 2

False

0 > -2

True

-2 > -5 + 4

False

< operator

This is the less than operator: <. It returns True if the value on the left is less than the value on the right. Otherwise it returns False.

2 < 1 # no, 2 is not less than 1

False

1 < 2 # yes, 1 is less than 2

True

2 < 2

False

0 < -2

False

-2 < -5 + 4

True

>= operator

This is the greater than or equal to operator: >=. It returns True if the value on the left is greater than or equal to the value on the right. Otherwise it returns False.

5 >= 5

True

5 >= 3

True

<= operator

This is the less than or equal to operator: <=. It returns True if the value on the left is less than or equal to the value on the right. Otherwise it returns False.

-2 <= -2

True

-2 <= -1

True
Boolean Data Type Logical Operators