Coding Interview Practice: MergeSort merge step

merge.py

#
# lessons learnt:
#
# - python's list has no find() method -- the correct name is index()
# - next() is a built-in Python function -- http://stackoverflow.com/questions/1733004/python-next-function
#
def merge(arrays):
    result = list()
    while arrays:
        heads = [a[0] for a in arrays]
        next_value = min(heads)
        arrays[heads.index(next_value)].remove(next_value)
        result.append(next_value)
        arrays = filter(None, arrays)
    return result

if __name__ == "__main__":
    arrays = [[0, 5, 8, 9], [1, 2, 7], [10]]
    print merge(arrays)