I have a .xlsx file to edit, I found openpyxl could manipulate Excel 2007 files.
I only want to change the value in some cells and leave other settings unchanged.
Styles aren't fully supported yet in openpyxl. Make sure you're using the latest version (1.5.3 as of now), as it recently improved its style capabilities.
The xlwt has more complete formatting for .xls files, but doesn't support xlsx as of yet.