Merging simple lists into a nested list

Hi All!

I may have missed it/forgotten from the basic lessons, but I need help merging two or more lists into a single list of nested lists.

For example, if I have
l1 = [1, 2, 3]
l2 = [a, b, c]

I would like the output to be:
l3 = [[a, 1], [b, 2], [c, 3]]

I know how to use the zip() function, but the output there are tuples and I want to be able to combine the lists in a way that can be further extracted or edited. Obviously, just rewriting a nested list is easy when the number of items is small, but I am trying to this with lists that are 20 items or more each.

Thank you all in advance for your help!

This may work to create an array that contains arrays made from each item ascending the index of the initial array (i.e. l1)

l1 = [1, 2, 3]
l2 = ["a", "b", "c"]

def func(l1, l2):
    x, outputarray = 0, []
    while x < len(l1):
    return outputarray 

resultingarray = func(l1, l2)
print("resultingarray is", resultingarray)