openpyxl is a Python library to read/write Excel 2010 xlsx/xlsm/xltx/xltm files. It was born from lack of existing library to read/write natively from Python the Office Open XML format. All kudos to ...

How to compare two excel files for differences? Using this web tool, you can compare Excel document easily. Just select first/original file in left window and second/modified file in right window.