Projecting variables in python when applying the map function

Question

Is it possible to project the second argument of the inner function when mapping across a set of items in Python?

when using map with the monadic use of the int cast function it works simply:

list(map(int, ["4","3","1","2"]))

But I want to cast multiple binary digits to an int using int's dyadic form int("1101",2) using map:

list(map(int(,2), ["1101","0001","1100","0011"]))

Answer 1

you need lambda

list(map(lambda x : int(x,2), ["1101","0001","1100","0011"]))

but when you need list, lambda and map, that's a dead giveaway that you just need list comprehension:

[int(x,2) for x in ["1101","0001","1100","0011"]]

(clearer, shorter, and faster than map when lambda is required)

Answer 2

The int function has signature:

int(x, base=10)

So we can make a partial, where we assign base=2 to:

from functools import partial

list(map(partial(int, base=2), ["1101","0001","1100","0011"]))

partial takes as first parameter a function (here int) as well as other (named and unnamed) parameters. It constructs a function that will fill in some parameters itself.