University:
Boston University
Course:
MET CS 201 | Introduction to Programming
Academic year:

2022
Views:

460

Pages:

9
Author:

vratitiea8k

Python with Turtle What is Python with Turtle? Python with Turtle is a Python library that enables you to create virtual drawings and shapes. The “turtle” is a the pen that you use to draw. History - Part of the original Logo programming language developed by Wally Feurzig and Seymour Papert in 1966 - Turtles are a type of educational robots designed in the 1940s, that are typically designed low to the ground. Some turtles are speciﬁcally designed to have pens attached to the back of them so they can draw on large sheets of paper. - It uses tkinter for the underlying graphics, it needs a version of Python installed with Tk support. A Basic Program on Turtle ● There is no programming language called ‘turtle’, so we use Python whenever we import the turtle library. Because of this, on our ﬁrst line of code, we need to tell our computer we are using turtle: >> import turtle ● Next, we need to name our turtle, and turtle will respond to whatever name you give it. We are just going to name it “alfred”. >> alfred = turtle.Turtle() ● After that, we can make alfred move forward, and we can do this by using the forward command in turtle. Whatever number you put in the parentheses is how many pixels alfred will move forward. >> alfred.forward(40) A Basic Program on Turtle (Part 2) ● Similarly, we can have alfred move backwards. >> alfred.backward(40) ● We can also increase the speed of alfred by using the following command: >> alfred.speed(100) ● Now, we want to be able to control alfred with the arrow keys, so we will put down the following function to allow the screen to follow certain commands. >> screen = turtle.Screen() You can also give your screen a different name A Basic Program on Turtle (Part 3) ● Next, we need to create functions that are going to be in charge of alfred moving up, down, left, and right. >> def moveUp(): >> def moveRight(): alfred.setheading(90) alfred.setheading(0) alfred.forward(50) alfred.forward(50) >>def moveDown(): >> def moveLeft(): alfred.setheading(-90) alfred.setheading(180) alfred.forward(50) alfred.forward(50) A Basic Program on Turtle (Part 4) ● Now we need to make alfred move in each direction when the corresponding key is pressed, we can do this by using the following commands that call the functions we made earlier: >>screen.onkey(moveUp ,”Up”) >>screen.onkey(moveDown, ”Down”) >>screen.onkey(moveRight ,”Right”) >>screen.onkey(moveLeft, ”Left”) ● Next, we need to make the Screen listen to the commands we are giving it >>screen.listen() Turtle Functions - turtle.Turtle() - - turtle.Screen() - - Moves Turtle Backward .left(int) - - Moves Turtle Forward .backward(int) - - Makes a Screen - Turns Turtle Left .right(int) - Turns Turtle Right .color(string or int,int,int). - - - Enables the turtle to move around without drawing - Enables drawing - Changes Turtle Size Changes Turtle Speed .shape(string). - Changes Turtle Shape Ending spot for ﬁlling color .xcor() - - Starting spot for ﬁlling color .end_ﬁll(). - - Sets to ﬁll in something drawn by the turtle with a color .begin_ﬁll(). - .speed(int) - - .ﬁllcolor(string) - .pensize(int) - - Changes Turtle Color .pendown(). - - - .penup(). - .forward(int) - - Makes a Turtle Find X coordinate of Turtle .ycor() - Find Y coordinate of Turtle Turtle Functions Continued - .goto(int, int). - - .circle(int) - - Set orientation of the Turtle .home(). - - Draws a Circle - Send Turtle to 0, 0 and makes it go back to its starting orientation .undo(). - Undo the Turtle last actions .position() - - - Returns the angle from the Turtle’s position to the position given .heading() - - Returns Turtle’s position .towards(int, int) - .setheading(int) - - Moves Turtle to a speciﬁc Spot Returns Turtle’s current heading .distance(int, int or turtle). - Returns distance between turtle and given point or anothers turtle - .degrees(int) - - .radians() - - Set Angle Measurement Units to Radians .isdown() - - Set Number of Degrees for a Full Circle Check to see if Pen is Down or Up .reset(). - Delete All of Turtle’s Drawings, re-center Turtle, put everything back to default