I'm using openpyxl to put data validation to all rows that have "Default" in them. But to do that, I need to know how many rows there are.
I know there is a way to do that if I were using Iterable workbook mode, but I also add a new sheet to the workbook and in the iterable mode that is not possible.
ws.max_row
will give you the number of rows in a worksheet.
Since version openpyxl 2.4 you can also access individual rows and columns and use their length to answer the question.
len(ws['A'])
Though it's worth noting that for data validation for a single column Excel uses 1:1048576
.