Any object can be tested for truth value, for use in an if or while condition or as operand of the Boolean operations below. The following values are considered false:
None
False
0, 0L,
0.0, 0j.
'', (), [].
{}.
False.3.1
All other values are considered true -- so objects of many types are always true.
Operations and built-in functions that have a Boolean result always
return 0 or False for false and 1 or True
for true, unless otherwise stated. (Important exception: the Boolean
operations "or" and "and" always
return one of their operands.)