'Write a column of data starting from (row, col).
Args:
row:    The cell row (zero indexed).
col:    The cell column (zero indexed).
data:   A list of tokens to be written with write().
format: An optional cell Format object.
Returns:
0:  Success.
other: Return value of write() method.'

@convert_cell_args
def write_column(self, row, col, data, cell_format=None):

    for token in data:
        error = self.write(row, col, token, cell_format)
        if error:
            return error
        row += 1
    return 0
