Dear Pavel, thank you very much for this.
Yes, that is indeed the case; mostly for educational purposes, myself along with some undergraduate students are trying to perform a couple of non-usual streamlined analyses on .mtz files, such as calculating Unitary SF or validating r_values upon symmetry expansion.
However, I have zero programming skills in python or any other languages, hence this request.
Therefore, it would be extremely helpful and appreciated if you could write such a code for us. There is no need for the code to write any output file, just calculate r_work and r_free from Fobs and Fcalc from an input .mtz.
We thank you again for your attention and time.
Best wishes,
Andre.