Issue #407 duplicate
This section of code in iter_worksheet.py, (function _get_row), references the variable "row" without it having been assigned:
if max_col is not None: while col_counter <= max_col: yield ReadOnlyCell(self, row, None, None) col_counter += 1
Introduced apparently in revision 2.1.4.
I encountered it when loading a workbook with use_iterators=True.