For this project, you will write most of the code, but it will be in only two files, and you will have comments as a guide. When you actually run the program, it will print off information about a group of shapes -- circles, triangles, and rectangles. This will be accomplished with three files:

• shape_types.py:
  • This file will contain code for three class definitions: Rectangle, Circle, and Triangle
  • Each class will have certain attributes:
    • A Circle will have a radius.
    • A Rectangle will have a length and width.
    • A Triangle will have three side lengths.
  • Each class will have a constructor that sets up information about a shape's attributes
  • Each class will have a string method (def __str__(self):) that produces a string with information about the shape's dimensions. (See sample output.)
  • Circle and Rectangle will have getters and setters for their attributes. The setters will verify that the new attribute values are both greater than zero.
  • Triangle will have neither a getter nor a setter.
  • Each class will have an area() method that calculates the area appropriately
• shape_cli.py will:
  • Read and execute the code from shape_types.py
  • Create an empty list
  • Read in data from shapes.dat (as tuples) to create Rectangle, Circle, and Triangle objects -- and append them to the list
  • Print out the different information about the shapes
  • (Some steps are not spelled out explicitly here, but they are still necessary.)
• shapes.dat will:
  • Contains a series of (pickled) tuples of information about a shape's dimensions.
  • Terminates with a value of None.
  • The length of the tuple is your clue as to which shape is intended:
    1. A tuple of length 1 indicates a Circle, where the single value is the radius.
    2. A tuple of length 2 indicates a Rectangle, where the two values are the length and width.
    3. A tuple of length 3 indicates a Triangle, where the three values is are the three side lengths.
  • This file is there for your testing purposes, and you do not need to upload it because I will use a different data file when grading.
  • You should not alter this file in any way, though you may wish to create your own separate data file for extra testing.

Some additional points of consideration:

• You will probably find it helpful to write the shape classes first, so that you can test them out to make sure they work correctly.
• You can do this by completing the code for shape_types.py and then running it from the Python interpreter prompt:

              exec (open ("shape_types.py").read())

• You may need to edit the file path, depending on your current working directory in the interpreter.
• Then, once you know the shape classes are working correctly, you can complete the code for shape_cli.py and run and test it.