In order to change the world using Python, we will need to open the Python interface. Press the Tab key to free yourself from the Minecraft window. Begin by clicking the Raspberry again and clicking on Programming, followed by Python 3.
A window should open with license text and a >>> prompt. This is a Python shell window. We are not going to be programming here. Instead, head to the File menu and click New File. An empty window should open. Drag that window over so it is next to, but not on top of, the Minecraft window.