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 truex == 4 is false |
!= |
a != b means a is not equal to b |
x != 3 is falsex != 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 truex < 3 is false |
> |
a > b means a is greater than b |
x > 2 is truex >3 is false |
<= |
a <= b means a is less than or equal to b |
x <= 4 is truex <= 3 is truex <= 2 is false |
>= |
a >= b means a is greater than or equal to b |
x >= 2 is truex >= 3 is truex >= 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.