We have a few customers in reinsurance, and for the most part the goal is to do the opposite of what the python solutions try to do. Instead of integrating foreign stuff into existing workbooks, the goal is to retain the existing worksheets as source of truth and build modern tools around the files. The most common use case is building out a web interface to replicate the Excel formula engine.

In the python space, there are libraries like openpyxl and xlrd, but the real hurdle is introducing python into an ecosystem which otherwise has no natural knowledge. JavaScript is the language of choice for modern Excel addins as Excel provides an actual API for it https://docs.microsoft.com/en-us/office/dev/add-ins/referenc...