if, else, and elif Statements

3. Equality and relational operators

Equality and relational operators

Equality operators

An equality operator checks whether two operands' values are the same (==) or different (!=). 

Note that equality is ==, not just =.

Equality operators Description Example (assume x is 3)
== a == b means a is equal to b x == 3 is true
x == 4 is false
!= a != b means a is not equal to b x != 3 is false
x != 4 is true

An expression evaluates to a Boolean value.
A Boolean is a type that has just two values: True or False

Relational operators

A relational operator checks how one operand's value relates to another, like being greater than.

Relational operators Description Example (assume x is 3)
< a < b means a is less than b x < 4 is true
x < 3 is false
> a > b means a is greater than b x > 2 is true
x >3 is false
 <=  a <= b means a is less than or equal to b x <= 4 is true
x <= 3 is true
x <= 2 is false
 >=  a >= b means a is greater than or equal to b x >= 2 is true
x >= 3 is true
x >= 4 is false

Operator chaining

Python supports operator chaining.
Example:
a < b < c
determines whether b is greater-than a but less-than c.
Chaining performs comparisons left to right,
evaluating a < b first.
  • If the result is true, then b < c is evaluated next.
  • If the result of the first comparison a < b is false, then there is
  • no need to continue evaluating the rest of the expression.