Hi @GeoMatteo
Python support is not included in QField (and not planned for anytime in the near future).
However, it is now possible to extend QField functionality with plugins Plugins - QField Ecosystem Documentation
The API is continuously extended based on real world needs.
There is also the possibility to have QML widgets in QField which can include logic that works in both QGIS and in QField The new QML widgets in QGIS – When widgets get unbridled – OPENGIS.ch .