[EMAIL PROTECTED] wrote:
> def ormap(b,L):
> if True in map(b,L): return True
> else: return False
>
> Is this good enough?
No, because
- (as Felipe observed) it doesn't shortcut, i. e. it always evaluates
b(item) for all items in L.
- it creates a temporary list
- if truthvalue: return True
else: return False
is redundant and just plain ugly
Just write
return truthvalue
or, when truthvalue may consume a lot of memory,
return bool(truthvalue) # or: return not not truthvalue
Which gives:
def andmap(predicate, items):
return False not in (predicate(item) for item in items)
def ormap(predicate, items):
return True in (predicate(items) for item in items)
> andmap((lambda t: boolean(t)),L)
Superfluous lambda alert: make that
andmap(boolean, L)
Python 2.5 will feature similar functions any() and all() which seem to have
a fixed predicate == bool, though.
Peter
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