据我所知，df.style仅在将数据框导出为HTML时使用.

As far as I know, df.style is only used when exporting the dataframe to HTML.

对于Excel，如果我建议使用编写的库，请参见以下示例代码(请注意，由于使用整数作为标题存在一个小问题，因此此列标题使用了字符串):

For Excel, If I may suggest using a library that I wrote, see this example code (Note that this is using strings for the column headers since there is a small issue with using integers as headers):

import pandas as pd
from StyleFrame import StyleFrame, Styler

df = pd.DataFrame({'1': [None, None, 33, None],
                   '2': [23, None, None, None],
                   '3': [None, 54, None, 24]})

sf = StyleFrame(df)
style = Styler(bg_color='yellow')
for col_name in df.columns:
    sf.apply_style_by_indexes(sf[~df[col_name].isnull()], cols_to_style=col_name,
                              styler_obj=style)
sf.to_excel('test.xlsx').save()

这将生成以下Excel:

This generates the following Excel: