In addition, you can convert all the sheets in one pass by specifing a %d or a %s format specifier in the output file name: $ python ssconverter.py file1.xls file1-%d.csv $ python ssconverter.py file1 ...

Readers suggest tools for to address the daunting problem of converting XML formatted data to CSV. Things may come and things may go, but the need to convert data formats will go on forever.