Regarding the implementation of all(), reduce() would probably give slightly better performance than a python loop although I think that reduce() will not be present in python 3000 as a built-in.

If using a loop, the following is a slightly more efficient implementation than the one above (there is no point in continuing the iteration if an item is not True).


def all(items):
for item in items:
if not item:
return False
return True


The cast to bool is just playing it safe, though it might be redundant


def all(items):
result = True
for item in items:
result = result and item
return result


I like the use of list comprehensions is great though. What is explicit cast to bool for?

Great article, I was thinking of doing this for a project of mine as well.