Python iterate two lists different length

I am attempting to merge two python lists, where their values at a given index will form a list [element] in a new list. For example:

merge_lists[[1,2,3,4], [1,5]] = [[1,1], [2,5], [3], [4]]

I could iterate on this function to combine ever more lists. What is the most efficient way to accomplish this?

Edit [part 2]

Upon testing the answer I had previously selected, I realized I had additional criteria and a more general problem. I would also like to combine lists containing lists or values. For example:

merge_lists[[[1,2],[1]] , [3,4]] = [[1,2,3], [1,4]]

The answers currently provided generate lists of higher dimensions in cases like this.