Python change type of whole list?

Python 2:

map(int, ['1','2','3']) # => [1,2,3]

…

def foo(l, dtype=long):
    return map(dtype, l)

In Python 3, map() returns a map object, so you need to convert it to a list:

list(map(int, ['1','2','3'])) # => [1,2,3]

…

def foo(l, dtype=long):
    return list(map(dtype, l))