Create (nested) List from two Lists in Python

Use the builtin zip function. It's exactly what you want. From the python manuals:

>>> x = [1, 2, 3]
>>> y = [4, 5, 6]
>>> zipped = zip(x, y)
>>> zipped
[(1, 4), (2, 5), (3, 6)]

Or if you want a list of lists, instead of a list of tuples, you use zip with a list comprehension:

>>> zipped = [list(t) for t in zip(x, y)]
>>> zipped
[[1, 4], [2, 5], [3, 6]]

Try:

listone = [1,2,3]
listtwo = [4,5,6]

merged = map(list, zip(listone, listtwo))

zip(listone, listtwo) will return a list of tuples. Since you want a list of lists you need to convert each tuple to a list. map(list, list_of_tuples) call will do exactly that.