There are times when filtering (either using filter or a list comprehension) doesn't work. This happens when some other object is holding a reference to the list you're modifying and you need to modify the list in place.
for name in names[:]:
if name[-5:] == 'Smith':
names.remove(name)
The only difference from the original code is the use of names[:] instead of names in the for loop. That way the code iterates over a (shallow) copy of the list and the removals work as expected. Since the list copying is shallow, it's fairly quick.
