TypeError: Argument 2 must support iteration (even though it does?)

Question

I'm new to python and am getting an error with the map function that doesn't make sense to me. When I call the function with a list as the second parameter it returns the error 'TypeError: Argument 2 must support iteration' which confuses me because a list should support iteration.

import numpy as np
print(np.array(map(int, raw_input().split().reverse()), float))

The code is meant to take in a list, and print out a numpy that is the reverse of the list. Any help as to why the second paramter isn't iteratable would be appreciated. Thanks!

Answer 1

list.reverse() function reverses the list in-place and returns None. If you want to write this as one line you may write reversed(raw_input().split()) instead.

Answer 2

.reverse() does the reverse in-place and returns None.

Get rid of the .reverse() and call reversed() instead like so, which should fix your issue:

import numpy as np
print(np.array(map(int, reversed(raw_input().split())), float))