I finished one short Python course and got the certificate. A second course isn't very useful (using Python to automate Excel); not sure if I'll bother to "test out of it" or just drop it. The best way to automate Excel is to learn VBA (which is built in) and use that. Just output the data to CSV, and then call the VBA macro to do whatever you think you need Excel for.

The openpyxl library is annoying. If you're "married" to Python, you're better off using Gnuplot, Octave or other data visualization tools rather than Excel.