Remix your first Trinket
We’ll be using trinket.io for many of the exercises in this class. Trinket is an online Python interpreter designed for education. With it, you can run, remix, and share code from your browser.
First, click Run to see what the code does. Then, click Remix and create a Trinket account to save a copy of this Trinket to your account:
You’ll now be able to save your updates right here.
Here’s a chat box for dropping share links:
What can Turtles do?
Turtles were deisgned by programmers (all programs are, of course) and these programmers thought of some cool things they thought would be useful to include in their code. Later in the course we’ll learn how to add our own cool abilities to turtles. First, let’s see some of the things they can do.
All of the examples below assume you’ve already created a turtle named tina.
Shape
Turtles can be all sorts of shapes, the coolest of which is turtle shape.
tina.shape("turtle")
circle and arrow are two others. We’ll learn later how to make our own.
Forward, Backward, Left and Right
Turtles are great for learning because you can treat them like little robot animals. Tell them to go forward or backward a certain number of pixels.
tina.forward(100)
tina.backward(100)
Now, a square:
tina.forward(100)
tina.left(90)
tina.forward(100)
tina.left(90)
tina.forward(100)
tina.left(90)
tina.forward(100)
The number passed to left and right should be a number of degrees. See what
happens if you pass in a number bigger than 360
Ah, the pen
Our Turtles are actually mutant (though not ninja) turtles. You may have noticed that
they draw anywhere they move. We can control that behavior with .penup():
# No line:
tina.penup()
tina.forward(100)
# Yes line:
tina.pendown()
tina.backward(100)
Color!
Turtles can change into all kinds of awesome colors.
# Red!
tina.color("red")
tina.forward(100)
# No, Blue!
tina.color("blue")
tina.backward(100)
Stamp
Turtles can make a stamp of their shape that stays there even if they leave:
tina.forward(100)
tina.stamp()
tina.backward(100)
Circle
You guessed it:
tina.forward(100)
tina.circle(10)
tina.backward(100)
Fill
Turtles have a fill mode that will fill in a shape.
tina.fill(True)
tina.forward(100)
tina.left(90)
tina.forward(100)
tina.left(90)
tina.forward(100)
tina.left(90)
tina.forward(100)
tina.fill(False)
Goto
Know exactly where you want your turtle to go? Make here go there:
tina.goto(100,100)
See if you can figure out the extent of the coordinate system.
Setx
Set the x coordinate.
tina.setx(100)
Sety
Set the y coordinate.
tina.sety(100)
Hide
Peek-a-boo turtles.
tina.hideturtle()
Write
Turtles are literate.
tina.write("Heck Yeah!", None, "center", "16pt bold")
The list of arguments that write takes is an example of something that you’ll need documentation to really understand. Here are the docs
The Screen object
When you make a Turtle, there’s an invisible Screen object that the turtle moves on. You can explictly create this object and then do things like change its color.
Try out this code:
myscreen = turtle.Screen()
myscreen.bgcolor("blue")There are several other cool things Screens can do but we won’t get to them til later. If you’re interested, look them up! You’ll be able to use them in your first homework.