Boolean operators

• These receive only Booleans as operands and give a Boolean as result.

Examples

Example 1

if (x >= 1) and (x <=10):
  print('x is between 1 and 10 inclusive')

Example 2

if not (x == ''):
  print('x is not the empty string')

Example 3

if (x < 1) or (x > 10):
  print('x is not between 1 and 10')

Example 4

message = "you fool!"
if "fool" not in message:
  print("Message does not contain offensive language")

Short-circuit evaluations

In (A and B), if A is false, then so is the expression, and there is no need to evaluate B.

In (A or B), if A is true, then so is the expression, and there is no need to evaluate B.

Keep an eye on that!

Remember precedence order!

1. Parentheses: ()
2. Exponents: **
3. Multiplication, divisions and modulus: * / // %
4. Addition and subtraction: + -
5. Comparisons: <= < >= > == != is in
6. Boolean not
7. Boolean and
8. Boolean or