I have the reverse problem as described in this question: On Preventin pandas from interpreting 'NA' as NaN. I work with older English text data and want to write the word "nan" (i.e. Modern English 'non(e)') into an Excel file. On the one hand, I want Excel to show this word as "nan" for a particular column. On the other hand, I don't want empty cells elsewhere in my dataframe be filled with whatever other NaN-replacements you can think of in the Excel file. Instead, what I get when I use df.to_excel() is an empty cell. Many thanks in advance. Continue reading...