Checking for empty cells with OpenPyXl

Question

I've poured over numerous versions of this same question, but simply cannot find a working solution for looping through a group of cells and checking for empty ones.

Here's my code:

wb = openpyxl.Workbook(write_only=False)
sheet = wb.get_sheet_by_name('Sheet')
for i in range(1, 20):
    if sheet.cell(row=i, column=1).value == None or 'None':
        print('Space' + str(i))
        sheet.cell(row=i, column=1) = i
    else:
        pass

wb.save('filename.xlsx')

But for some reason it writes to the empty cells AND overwrites the cells which had values written in them.

I comment out the loop I find that if I run the code it erases everything that was manually written into the spreadsheet to begin with. Maybe that's part of the problem?

Also I'm using LibreOffice if that makes a difference

Answer 1

What Charlie mentions is of course correct.

Non empty strings in Python evaluate to True , so you are actually testing if cell value is None or if bool('None') , and the later is always True , hence your condition always evaluates to True .

To address your specific case I'm not sure why you are trying to test for an empty cell with 'None' .

In case you really want to do this your condition should look like this:

if sheet.cell(row=i, column=1).value in [None,'None']

If you want test for None or an empty string, so None or '' then of course your condition should be:

if sheet.cell(row=i, column=1).value in [None,'']

Hope this gets you on the right track..