If you want to convert each of the lists to a list of integers, you can do
a, b = ['1','2','3'], ['1','2']
print(list(map(lambda x: map(int,x), [a, b])))
# [[1, 2, 3], [1, 2]]
which can be assigned to a
and b
back, like this
a, b = map(lambda x: map(int,x), [a, b])
If you want to chain the elements, you can use itertools.chain
, like this
from itertools import chain
print(list(map(int, chain(a,b))))
# [1, 2, 3, 1, 2]
Edit: if you want to pass more than iterable as arguments, then the function also has to accept that many number of parameters. For example,
a, b = [1, 2, 3], [1, 2, 3]
print(list(map(lambda x, y: x + y, a, b)))
# [2, 4, 6]
If we are passing three iterables, the function has to accept three parameters,
a, b, c = [1, 2, 3], [1, 2, 3], [1, 2, 3]
print(list(map(lambda x, y, z: x + y + z, a, b, c)))
# [3, 6, 9]
If the iterables are not of the same size, then the length of the least sized iterable will be taken in to consideration. So
a, b, c = [1, 2, 3], [1, 2, 3], [1, 2]
print(list(map(lambda x, y, z: x + y + z, a, b, c)))
# [3, 6]