[Week 4]: Turtles and For Loops¶

Agenda¶

Complete the refresher exercises: Week 4 Refresher Exercises.
Listen to me tell you about for loops and turtles!
Work on the Week 4 exercises: Week 4 Exercises
Work on these at home (or in class, if you finish fast enough): Week 4 Takehome Exercises

Review¶

Terms you should know¶

for loops
the loop variable
range

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:

bob.forward(100)
bob.left(90)

There are many things you can do:

bob.shape('turtle') # change the shape
bob.stamp() # stamp the shape onto the board
x=100
y=100
bob.goto(x,y) # go to this position
bob.penup() # stop drawing when the turtle moves
bob.pendown() # start drawing again