Python

<code>def add_lists(a, b):
    """
      >>> add_lists([1, 1], [1, 1])
      [2, 2]
      >>> add_lists([1, 2], [1, 4])
      [2, 6]
      >>> add_lists([1, 2, 1], [1, 4, 3])
      [2, 6, 4]
    """
    new_list = []
    i = 0
    while i < len(a):
        new_list += a(i) + b(i)
        i += 1
    return new_list

if __name__ == '__main__':
    import doctest
    doctest.testmod()</code>

TypeError: 'list' object is not callable

How can I fix this?

>>4
Am I supposed to feel bad for asking a /prog/ related question in /prog/?  No doubt I'm new to the language and programming in general.  If you'd like me to leave quickly/improve my skills, you'd answer the question.  Anything less is an act of trolling.  Why post on a /prog/ if you've no intention of discussing /prog/ related material?  Perhaps you're incapable of debugging a program so simple? 

tldr: I'm new, don't be an ass, be helpful