def remove_duplicates(seq):
    """
    Removes duplicates from a list.

    This is the fastest solution, source:
        http://www.peterbe.com/plog/uniqifiers-benchmark

    Input arguments:
        seq -- list from which we are removing duplicates

    Output:
        List without duplicates.

    Example:
        >>> seq = ['a', 'a', 'b', 'c', 'a']
        >>> print remove_duplicates_from_list(seq)
        ['a', 'b', 'c']
    """
    seen = set()
    seen_add = seen.add
    return [x for x in seq if not (x in seen or seen_add(x))]