@Gabriel2020 maybe you could provide us with more details about your workflow.
If you encounter a problem you also might want to ask a question in the KNIME Forum. To do that: read how to write a good forum entry or ask for help, then provide a sample workflow and maybe provide a detailed log file.
Were you able to check your Python installation? You might have to familiarise yourself with the way the Python nodes handle their in and outputs. Not sure what type of data your script would create.