Hi @lska,
This is possible either with Invoke Python activity or via PowerShell or start process activities.
This post goes over the three approaches to integrate Python into your UiPath project.
As suggested in the other post. Python need not be installed in the system. All the modules you use need to be installed (via pip or conda) prior to integrating it with Python.
You can also look at using Embedded python, which is a standalone portable version of Python, no installation required.