[Week 4]: Turtles and For Loops

Turtles cheat sheet

In class Exercises


Take home exercises

Link to exercises


From Simple to Complex variables

There are two ideas you should combine in your head. The first is about simple variables. Simple variables have a single type. For example, a simple variable can be an integer or a string.

The other idea you should combine is code robots. We talked about code robots in class. Code robots have a very simple design: take an input, give an output.

Combining these ideas, we can talk about complex variables. Complex variables can have multiple simple variables inside them. They can also be several code robots in one.

Turtles are just this! Turtles can have multiple variables, like color and shape. They can also do multiple things. You can have it go forward or have it turn!

Summary of Turtles

Turtles are created from their factory.

import turtle
bob = turtle.Turtle()

Then, you can make it move and turn:


There are many things you can do:

bob.shape('turtle') # change the shape
bob.stamp() # stamp the shape onto the board
bob.goto(x,y) # go to this position
bob.penup() # stop drawing when the turtle moves
bob.pendown() # start drawing again

Lecture Slides