def range_boundaries(range_string):
    m = ABSOLUTE_RE.match(range_string)
    min_col, min_row, sep, max_col, max_row = m.groups()
    min_col = column_index_from_string(min_col)
    min_row = int(min_row)

    if max_col is None or max_row is None:
        max_col = min_col
        max_row = min_row
    else:
        max_col = column_index_from_string(max_col)
        max_row = int(max_row)

    return min_col, min_row, max_col, max_row
Convert a range string into a tuple of boundaries:
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/openpyxl-2.3.0-b2/openpyxl/utils/__init__.py/range_boundaries