Our snake moves at a constant speed, and cannot turn back on itself like the classic snake in the game. The game stops if the snake moves off the screen.

This covers these Python topics: writing functions and refactoring code. We start preparing to make the snake into a class rather than a list.

This is the agenda:

• a recap and explanation of the current code (as a reminder and a brief introduction for anybody joining the course for the first time)
• a short lesson to introduce writing functions
• improve the geometry to think of the snake as moving over squares on a board, rather than pixels. This makes the subsequent tasks easier.
• make our snake move at constant speed in the direction of the latest arrow key pressed.
• restrict the snake’s movement so that it cannot double-back on itself
• check if the snake has moved off the screen and end the game if so
• refactor the code and write a few functions: for example, to draw the snake, and to change the snake's direction

Full details on the six week course here.