# First, install python or python3...
sudo apt-get install python
#or
sudo apt-get install python3
# Then, run your python file...
python /path-to-file/pyfile.py #or
python3 /path-to-file/pyfile.py
#Example
python /home/person/randomfile.py #or
python3 /home/person/randomfile.py
# Hope this helped :)