builtin functions for and and or?

[Steven Bethard]

Roose wrote:
> I need this a lot: a one line way to do a n-ary and or 'or'.
> 
> e.g.,
> 
> result = True
> for x in L:
>   if not boolean_function(x):
>     result = False
> 
> or
> 
>>>>reduce(operator.__and__, [boolean_function(x) for x in L)

Can you use itertools?

py> def boolfn(x):
...     print "boolfn: %r" % x
...     return bool(x)
...
py> True in itertools.imap(boolfn, ['a', '', 'b'])
boolfn: 'a'
True
py> True in itertools.imap(boolfn, ['', '', ''])
boolfn: ''
boolfn: ''
boolfn: ''
False
py> False in itertools.imap(boolfn, ['a', '', 'b'])
boolfn: 'a'
boolfn: ''
True
py> False in itertools.imap(boolfn, ['a', 'a', 'b'])
boolfn: 'a'
boolfn: 'a'
boolfn: 'b'
False

It even shortcircuits when appropriate.

Steve