Answer by Superpaul for Finding the average of a list

Both can give you close to similar values on an integer or at least 10 decimal values. But if you are really considering long floating values both can be different. Approach can vary on what you want to achieve.

>>> l = [15, 18, 2, 36, 12, 78, 5, 6, 9]>>> print reduce(lambda x, y: x + y, l) / len(l)20>>> sum(l)/len(l)20

Floating values

>>> print reduce(lambda x, y: x + y, l) / float(len(l))20.1111111111>>> print sum(l)/float(len(l))20.1111111111

@Andrew Clark was correct on his statement.