Project 2: A Shape Collection
The goal of this assignment is to give you practice in creating and using functions and function parameters in python. You'll continue to create shapes using turtle graphics, just like we did in lab.
The end result of the assignment should be a representation of a place on the Colby campus.
Make a copy of your lab2.py file and rename it shapes.py. Delete the
main code from the file so that only the import statements and the
functions remain. You should not have any top level code in the
Your first task is to create a main.py file that imports your shapes.py functions. To do this, create a file called main.py in a text editor, and at the top (after your name and a date) put the following.
In your main.py file, make a function called colby1. Put a single call to the colby1 function at the end of the file, followed by a raw_input call.
Write some python code in your colby1 function that calls some of the functions from your shapes.py file to draw a simple image. Note that to call a function from your shapes file you have to prepend shapes. in front of the function name. For example shapes.block( 10, 10, 20, 30 ) would be how you would call the block function.
You can run your main.py file using:
You don't need to save this image, as you'll be replacing the code in the colby1 function later on.
In your shapes.py file, make 2 more functions like the block
function that take in at least an x location, y location, and a scale
factor (or two). For example, you could make a triangle function or a
hexagon function. Put a print statement at the beginning of each
function and test them out by calling the functions in your main.py
Each of your shapes should draw properly no matter where it is drawn on the screen, what the scale factor is, or what the orientation of the turtle happens to be when the shape function executes. Test this out for all of your functions. In your writeup, include a picture demonstrating that your shapes function properly. This is required picture 1.
When you have a scene you want to save, make a screen capture of it on a mac using the key combination command-shift-4. Then hit space bar to get the camera icon and click the mouse to take the picture. The picture will automatically be saved to a file on your Desktop. You can then move and rename it to a more appropriate location.
In the shapes.py file, make 2 functions that draw iconic versions of
things that are going to be in your scene. These might be a bench, a
tree, or a building. They should incorporate several of the simpler
shapes from your library.
When you define these functions, they should all take at least three parameters. The first two (x0, y0) will define the starting location for the shape and the third should define the size of the shape. Feel free to add additional parameters as you like to control other aspects of the shape. As with the basic shapes, your shapes should draw properly at any scale, location, or turtle orientation.
For a little more detail on making aggregate shapes, see the geometric thinking page.
In both of of your new functions, use one or more of the basic shape functions to draw the shape. For example, a building might incorporate the block and triangle functions. Test out your new functions before proceeding. In your writeup, include a picture demonstrating that each of your shapes function properly
- Using the functions you created in steps 1 and 2, make a scene from Colby by writing code in the colby1 function in your main.py file that draws the shapes in appropriate locations. In your scene, make use of the fact that your functions can draw the shapes with different sizes in different locations. You can also use the random package and for loops to make more complex scenes. Save the image and include it in your writeup.
- Make a second Colby scene in a function colby2 in your main.py file. Save the image and include it in your writeup.
Each assignment will have a set of suggested extensions. The required tasks constitute about 85% of the assignment, and if you do only the required tasks and do them well you will earn a B+. To earn a higher grade, you need to undertake one or more extensions. The difficulty and quality of the extension or extensions will determine your final grade for the assignment. One complex extension, done well, or 2-3 simple extensions are typical.
- Make additional basic or complex shape functions that make use of your other shape functions.
- Make additional scenes that show creative use of functions, loops, or randomness.
- Make use of the for loop control structure from the lab (you can also read ahead in the book).
Make use of the random package to make your scene more
interesting. For example, if you import the random package into your
import randomThen you can use it to generate random integers using the following expression, where a and b are the upper and lower bounds of the random numbers you want.
- Make use of other turtle properties such as line width, color, and fill capability to make your shapes more interesting.
- Add additional parameters to your shapes to control properties like line width and color.
Make a new wiki page for your assignment. Put the label cs151S11proj2 on the page. Each of you needs to make your own writeup.
The purpose of the writeup is threefold. First, it gives you the opportunity to organize your thoughts about the project and see the larger purpose of the various tasks. In the case of this project, for example, the purpose was to introduce you to making use of functions as abstrations that let you create more and more complex graphical designs.
The second purpose is to give you practice with communicating the process and algorithms you developed to others. The writeup should capture the key points of the code you wrote. In the case of this project, describe how you divided up the task of making a scene. Did the division make sense? What program elements--functions, loops, variables--did you use to complete the task? Don't focus on the syntactic details, but on the overall structure and process your code uses to solve the problem. The best writeups are tutorials on the subject that would be appropriate for your peers not in the course.
The third purpose is to communicate to us that you understood the project and to show off any extensions or extra things you did to make it more interesting. We're also interested in knowing the primary things you learned from the project.
In addition to making the wiki page writeup, put the python files you wrote (shapes.py, main.py) on the Academics server in your handin directory.
In general, your writeup should follow the outline below.
- A brief summary of the task, in your own words. This should be no more than a few sentences. Give the reader context and identify the key purpose of the assignment.
- A description of your solution to the tasks, including any images you created. This should be a description of the form and functionality of your final code. You may want to incorporate code snippets in your description to point out relevant features. Note any unique computational solutions you developed. Code snippets should be small segments of code--usually less than a whole function--that demonstrate a particular concept.
- A description of any extensions you undertook, including images demonstrating those extensions. If you added any modules, functions, or other design components, note their structure and the algorithms you used.
- A brief description (1-3 sentences) of what you learned.
- Don't forget to label your writeup so that it appears in the listing on the main wiki page for the course. For this lab, use cs151S11proj2