Takes a two dimensional array and returns an new one where rows in the
    first become columns in the second.

def rows_to_columns(matrix):
#hammer
    """Takes a two dimensional array and returns an new one where rows in the
    first become columns in the second."""
    num_rows = len(matrix)
    num_cols = len(matrix[0])

    data = []
    for i in range(0, num_cols):
        data.append([matrix[j][i] for j in range(0, num_rows)])

    return data