Unable to export pandas dataframe into excel file
The problem you are facing is that your excel has a character that cannot be decoded to unicode. It was probably working before but maybe you edited this xls file somehow in Excel/Libre. You just need to find this character and either get rid of it or replace it with the one that is acceptable.
I am trying to export dataframe to .xls file using to_excel() method. But while execution it was throwing an error: "UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 892: ordinal not in range(128)". Just few moments back it was working fine. 
The code I used is: 
             :csv2.to_excel("C:\\Users\\shruthi.sundaresan\\Desktop\\csat1.xls",sheet_name='SAC_STORE_DATA',index=False).
csv2 is the dataframe. Why does this kind of error happens and how to avoid this is in the future?