Convert an Excel cell address to a tuple of (row, col)

excel_tuple.py

import re


def excel_tuple(address):
    """
    Takes an Excel address and converts it to a tuple.  Used as a helper for
    looking up (row, column) to pass into sheet.cell(row, col).
    >>> assert excel_tuple('A1') == (0, 0)
    >>> assert excel_tuple('Z10') == (9, 25)
    >>> assert excel_tuple('AAA999') == (998, 702)
    :type address: basestring
    :rtype: (int, int)
    """
    address = address.upper()
    m = _excel_tuple_regex.match(address)
    if not m or not m.group('col') or not m.group('row'):
        raise ValueError('Invalid Excel address {!r}'.format(address))
    col = -1
    seed = 0
    for c in reversed(m.group('col')):
        col += ord(c) - ord('A') + 26 ** seed
        seed += 1
    row = int(m.group('row')) - 1
    return row, col

_excel_tuple_regex = re.compile(r'^(?P<col>[A-Z]+)(?P<row>\d+)$')