openpyxl 3.0.9 how to get rid of default white colored background produced by openpyxl

[Ledocq Charles]

I'm trying to write a script to programmaticaly format the font, autofit columns width of an input.xlsx file which background is transparent (=no background color). Grid lines are visible when opened with gnumeric spreadsheet.

Till now, the python scripts to format the input.xlsx file are working well, excepted that their background is white. I have to open the input.xlsx file, select the whole sheet (Ctrl-A); then select the «background color» menu icon, and select ther «clear background» to get the grid lines visible.

Asking thei i.A. I got some codes attempting to delete backgrounds related codes,but without success.

example:

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wb = load_workbook("file.xlsx")
for ws in wb.worksheets:
    # remove sheet background image (internal attribute used by openpyxl)
    if hasattr(ws, "_background"):
        ws._background = None

    # clear tab color
    ws.sheet_properties.tabColor = None

    # optional: clear any per-cell fills (resets to no fill) If you only need to remove the sheet background image, omit the cell-fill loop.
    for row in ws.iter_rows():
        for cell in row:
            cell.fill = PatternFill()  # default empty fill

wb.save("file_no_bg.xlsx")

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or this one else:

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from openpyxl import load_workbook
from openpyxl.styles import PatternFill
import zipfile
import os

infile = "in.xlsx"
outfile = "out_no_bg.xlsx"

wb = load_workbook(infile)
for ws in wb.worksheets:
    # remove sheet background image (internal attr)
    if hasattr(ws, "_background"):
        ws._background = None
    # clear tab color
    ws.sheet_properties.tabColor = None
    # optional: clear cell fills
    for row in ws.iter_rows():
        for cell in row:
            cell.fill = PatternFill()  # resets to no fill

wb.save(outfile)

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It seems that a background comes embedded with openpyxl (mine is 3.0.9 version)

I'm wondering if the default openpyxl code could defaultly embed no background?

Thanks for your time and any workaround

Charlie