xlwt.Style.EasyXFCallerError: section 'fill' is unknown

I have a data frame in which I am making updations like writing and adding the background colour to a specific cell. It looks fine in dataframe. But when I convert dataframe to excel, found the below error.

df.to_excel("test_sheet.xls") is causing the error.

Traceback (most recent call last):
  File "scoring_model.py", line 441, in <module>
    pf = ScoringModel()
  File "scoring_model.py", line 12, in __init__
    self.start_scoring()
  File "scoring_model.py", line 185, in start_scoring
    df.to_excel("test_sheet.xls")
  File "D:\Projects\Scoring Model\venv\lib\site-packages\pandas\io\formats\style.py", line 187, in to_excel
    engine=engine)
  File "D:\Projects\Scoring Model\venv\lib\site-packages\pandas\io\formats\excel.py", line 662, in write
    freeze_panes=freeze_panes)
  File "D:\Projects\Scoring Model\venv\lib\site-packages\pandas\io\excel.py", line 1708, in write_cells
    style = self._convert_to_style(cell.style, fmt)
  File "D:\Projects\Scoring Model\venv\lib\site-packages\pandas\io\excel.py", line 1771, in _convert_to_style
    style = xlwt.easyxf(xlwt_stylestr, field_sep=',', line_sep=';')
  File "D:\Projects\Scoring Model\venv\lib\site-packages\xlwt\Style.py", line 733, in easyxf
    field_sep=field_sep, line_sep=line_sep, intro_sep=intro_sep, esc_char=esc_char, debug=debug)
  File "D:\Projects\Scoring Model\venv\lib\site-packages\xlwt\Style.py", line 638, in _parse_strg_to_obj
    raise EasyXFCallerError('section %r is unknown' % section)
xlwt.Style.EasyXFCallerError: section 'fill' is unknown

using python3.5 and xlwt 1.3 latest. Does anyone found the same error?

Thanks

Solution

Can you paste in the xlwt_stylestr?

There could be a typo in there [missing a space character?], as I checked the origin of the exception - https://github.com/python-excel/xlwt/blob/master/xlwt/Style.py#L639

Based on the comments, could you try:

xlwt_stylestr = 'pattern: pattern solid, fore_colour red;'

And then pass it to the write callable: https://xlwt.readthedocs.io/en/latest/api.html#xlwt.Worksheet.Worksheet.write styled.to_excel('styled.xlsx')

Can you try this:

def bg_red(val):
    # this will receive each value in the excel
    # so if you want to add conditional logic, you can
    # add here
    return 'background-color: red'

style_obj  = df.style.applymap(bg_red)
style_obj.to_excel('styled_doc.xlsx')

Refer this for more: https://pandas.pydata.org/pandas-docs/stable/user_guide/style.html