When trying to save a workbook with openpyxl i get a TypError - why?

Question

I'm building an application with which my company analyzes provided table data.

So far so good, but when I try to save the results to a workbook, I get a

TypeError: '<' not supported between instances of 'str' and 'int'

Does anyone know what to do about it?

this is a code snippet:

from openpyxl import *
from openpyxl.styles import Border, Side, Alignment, Font, PatternFill
from tkinter import *
import tkinter

root = tkinter.Tk()

# Properties of the GUI
root.geometry("120x80")
root.title("TOOL_1")

def create_new_workbook():
        global wb

        wb = Workbook()
        ss = wb.active
        ss.sheet_view.showGridLines = False
        ss.title = "Report"

        # Implement thick line vertically the seperate overview sheet
        bottom = Side(border_style='thick', color='000000')
        border = Border(bottom=bottom)

        col = ss.row_dimensions['23']
        col.border = border

        ss.merge_cells('B3:E6')
        ss['B3'].alignment = Alignment(horizontal='center',
                                       vertical='center')

        ss['B3'] = "TOTAL"
        total_label = ss['A3']
        total_label.font = Font(bold=True, size=24)

        ss['B7'] = "ZNr"
        ZNr_label = ss['B7']
        ZNr_label.font = Font(bold=True)
        ss.merge_cells('C7:E7')

        ss['B9'] = "DEP"
        DEP_label = ss['B9']
        DEP_label.font = Font(bold=True)
        DEP_label.fill = PatternFill(start_color='9BC2E6',
                                     end_color='9BC2E6',
                                     fill_type='solid')

        ss.merge_cells('C9:E9')
        deposit_amount = ss['C9']
        deposit_amount.fill = PatternFill(start_color='9BC2E6',
                                          end_color='9BC2E6',
                                          fill_type='solid')

        wb.save(r"Test1.xlsx")
        print("Saved")

button_create_new_workbook = Button(root, text="Create Workbook", command=create_new_workbook)
button_create_new_workbook.pack()
root.mainloop()

Answer 1

Your problem is this line:

col = ss.row_dimensions['23']

row_dimensions appears to accept either an integer or string input. However, when saving it requires an integer input, not a string. Admittedly, I found this quite hard to find and had to do a deep dive into openpyxl. The function that raises your error is:

def rows(self):
    """Return all rows, and any cells that they contain"""
    # order cells by row
    rows = defaultdict(list)
    for (row, col), cell in sorted(self.ws._cells.items()):
        rows[row].append(cell)

    # add empty rows if styling has been applied
    for row in self.ws.row_dimensions.keys() - rows.keys():
        rows[row] = []

    return sorted(rows.items())

Using print to isolate the rows, it gave these rows for your worksheet:

(3, [<Cell 'Report'.A3>, <Cell 'Report'.B3>, <MergedCell 'Report'.C3>, <MergedCell 'Report'.D3>, <MergedCell 'Report'.E3>])
(4, [<MergedCell 'Report'.B4>, <MergedCell 'Report'.C4>, <MergedCell 'Report'.D4>, <MergedCell 'Report'.E4>])
(5, [<MergedCell 'Report'.B5>, <MergedCell 'Report'.C5>, <MergedCell 'Report'.D5>, <MergedCell 'Report'.E5>])
(6, [<MergedCell 'Report'.B6>, <MergedCell 'Report'.C6>, <MergedCell 'Report'.D6>, <MergedCell 'Report'.E6>])
(7, [<Cell 'Report'.B7>, <Cell 'Report'.C7>, <MergedCell 'Report'.D7>, <MergedCell 'Report'.E7>])
(9, [<Cell 'Report'.B9>, <Cell 'Report'.C9>, <MergedCell 'Report'.D9>, <MergedCell 'Report'.E9>])
('23', [])

The last row is appended to the dictionary as it is empty, but has styling applied to it. However, you've input it as a string, which raises this error when trying to sort rows.items() . It may be unintential that row_dimensions allows strings. However, you can solve your problem by replacing

col = ss.row_dimensions['23']

with

col = ss.row_dimensions[23]