After installing Python on your system successfully, you can start the interactive python prompt by typing "python" in the command and press <enter>. It will show you some context information about python similar to this::

.. note:: On windows the installer is not always setting up the "path" correctly. If that is the case on your system, you probably didn't see this message before but have to follow the steps described on the `python docs <http://docs.python.org/using/windows.html#excursus-setting-environment-variables>`_ and **restart your command line**.

Those three ">>>" in the last line indicate that you are now in the interactive shell of python. Type for example::

press <enter> and see what happens. You will now see the phrase "Hello world" appear and then python will bring you back to the interactive input, where you could enter another command now::

Running python files

But you don't want to type everything into the Python shell everytime but have a file with commands for python to execute instead. In order to do that you can just pass a file name to the python command in your shell and it will execute that file. Let's try that. Just open the file "hello.py" in this directory in your favourite text editor and paste the print command from above. Now save that file, go back the command line and type::

When pressing <enter> now, the file is executed and you see the print as before. But this time, after python executed all commands from that file, it exited instead of going back to the interactive shell. In some opearting systems (and depending on your setup) you might also be able to just double click on the hello.py file to execute it