Python: Difference between filter(function, sequence) and map(function, sequence)

Question

I\'m reading through the Python documentation to really get in depth with the Python language and came across the filter and map functions. I have used filter before, but never

Answer 1

list(map(cube, range(1, 11)))

is equivalent to

[cube(1), cube(2), ..., cube(10)]

While the list returned by

list(filter(f, range(2, 25)))

is equivalent to result after running

result = []
for i in range(2, 25):
    if f(i):
        result.append(i)

Notice that when using map, the items in the result are values returned by the function cube.

In contrast, the values returned by f in filter(f, ...) are not the items in result. f(i) is only used to determine if the value i should be kept in result.

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In Python2, map and filter return lists. In Python3, map and filter return iterators. Above, list(map(...)) and list(filter(...)) is used to ensure the result is a list.