Parsing an HTML table to a multidimensional list, in python

# Credit for these functions go to reclosedev, from this Stackoverflow question:
# http://stackoverflow.com/questions/9978445/parsing-a-table-with-rowspan-and-colspan
def table_to_list(table):
    dct = table_to_2d_dict(table)
    return list(iter_2d_dict(dct))

def table_to_2d_dict(table):
    result = defaultdict(lambda : defaultdict(unicode))
    for row_i, row in enumerate(table.xpath('./tr')):
        for col_i, col in enumerate(row.xpath('./td|./th')):
            colspan = int(col.get('colspan', 1))
            rowspan = int(col.get('rowspan', 1))
            col_data = col.text_content()
            while row_i in result and col_i in result[row_i]:
                col_i += 1
            for i in range(row_i, row_i + rowspan):
                for j in range(col_i, col_i + colspan):
                    result[i][j] = col_data
    return result

def iter_2d_dict(dct):
    for i, row in sorted(dct.items()):
        cols = []
        for j, col in sorted(row.items()):
            cols.append(col)
        yield cols

# call with table_rows = extract_tables(table_el) where table_el is a lxml.html table element.