There is no direct method to call Python from QlikView. You can follow the steps mentioned below:
You can create a Python program that outputs CSV (or any file format that QlikView can read)
Invoke your Python program from the QlikView script: EXEC python3 my_program.py > my_output.csv
Read the output into QlikView: LOAD * FROM my_output.csv (...)
You need to make sure that the EXEC command requires the privilege "Can Execute External Programs" on the Settings tab of the script editor.