Logical Operators
Combine conditions with and, or and not.
Syntax
a and b
a or b
not aPython spells its logical operators as words, which keeps code readable.
and— True only if both sides are True.or— True if at least one side is True.not— inverts True to False and vice versa.
Python is lazy: with and it stops as soon as one side is False, and with or it stops at the first True.
Example
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When to use it
- A form validator requires both username and password to be non-empty using 'and'.
- A content filter blocks users who are either banned or under 18 using 'or'.
- A toggle function inverts a boolean flag with 'not' when a user clicks a switch.
More examples
and, or, not operators
Combines boolean expressions with 'and', 'or', and 'not' to evaluate compound conditions.
x = 10
print(x > 5 and x < 20) # True
print(x < 5 or x > 8) # True
print(not x == 10) # FalseShort-circuit evaluation
Shows short-circuit evaluation: 'and' skips the right side when the left is already False.
def expensive():
print('called expensive')
return True
# 'and' stops early if left side is False:
result = False and expensive() # expensive() never runs
print(result) # FalseLogical operators in access control
Uses 'or' to grant access if any one of several permission conditions is True.
is_admin = False
is_owner = True
resource_public = False
can_access = is_admin or is_owner or resource_public
print(can_access) # True
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