Question

I have written a code for detecting the EOF of an excel file using python:

row_no = 1
while True:
    x = xlws.Cells(row_no,1).value
    if type(x) is None:
        break
    else:
        print(len(x))
        print(x)
    row_no = row_no + 1

i expect the while loop will stop then x becomes a “blank cell”, which I support to be None, but it doesn’t work, and it go to len(x) and prompt me an error of NoneType has no len. Why?

Thanks!

Answer 1

This here is your problem:

if type(x) is None:

If x is None, its type is NoneType. Therefore, this is never true, so you never see the blank cell and you end up trying to get the length of None.

Instead, write:

if x is None: