I've written a function designed to delete all odd numbers from a list.
def purify(l):
for e in range(len(l)):
if l[e] % 2 != 0:
del l[e]
return l
v = [4, 5, 5, 6]
print purify(v)
The easiest way to do what you want may be by means of a list comprehension:
def purify(l):
return [e for e in l if not (e % 2)]