Python 2.7 quick reference |  |
Python 2.7 quick reference | |
A value of bool type represents a Boolean
(true or false) value. There are only two values,
written in Python as “True”
and “False”.
Internally, True is represented as 1 and
False as 0, and they can be used in
numeric expressions as those values.
Here's an example. In Python, the expression
“a <
babTrue if abFalse is ab
>>> 2 < 3 True >>> 3 < 2 False >>> True+4 5 >>> False * False 0
These values are considered False wherever
true/false values are expected, such as in an if statement:
The bool value False.
Any numeric zero:
the int value 0,
the float value 0.0,
the long value 0L,
or the complex value 0.0j.
Any empty sequence:
the str value '',
the unicode value u'',
the empty list value [],
or the empty tuple value ().
Any empty mapping, such as the empty dict
(dictionary) value {}.
The special value None.
All other values are considered True.
To convert any value to a Boolean, see Section 20.5, “bool(): Convert to Boolean”.