Hi Paul,
thanks for reaching out. You can now integrate Python scripts within REXYGEN 2.50.10 - for upgrade see post https://forum.rexygen.com/topic/120/installation-of-rexygen-2-50-10-testing
Python block documentaton: https://www.rexygen.com/doc/ENGLISH/MANUALS/BRef/PYTHON.html#x272-27100016
Let us know if it helped.
Regards,
Tomas