Python Boolean

Internal

• Python Language

Overview

A boolean can be True or False.

x = True
type(x)
<class 'bool'>

What is True?

The following values evaluate to False in Python. Everything else evaluates to True.

• boolean False
• None
• zero integer 0
• zero float 0.0
• empty string
• empty list []
• empty tuple ()
• empty dict {}
• empty set set()

Operators

OR: | and |=

assert (True | True)
assert (True or True)
assert (True | False)
assert (True or False)
assert (False | True)
assert (False or True)
assert not (False | False)
assert not (False or False)

l = [True, False]
b = False
for e in l:
    b |= e
assert b

l = [False, False]
b = False
for e in l:
    b |= e
assert not b

Note that + applied to booleans contest to integers.

AND: & and &=

assert (True & True)
assert (True and True)
assert not (True & False)
assert not (True and False)
assert not (False & True)
assert not (False and True)
assert not (False & False)
assert not (False and False)