If you wanted to concatenate arbitrary number of lists, you could do this:
In [1]: lists = [["a", "b", "c"], ["m", "n", "o"], ["p", "q", "r"]] # Or more
In [2]: lists
Out[2]: [['a', 'b', 'c'], ['m', 'n', 'o'], ['p', 'q', 'r']]
In [4]: list(map("".join, zip(*lists)))
Out[4]: ['amp', 'bnq', 'cor']