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Lab 11: Binary Search, Key Functions, 2D Lists

Goals

After the lab, you should be proficient at

  1. adapting binary search for use in another algorithm
  2. key functions used in sorting
  3. creating and processing 2D lists

Review

Review the slides for today.

Linux

Copy the entire directory /csdept/local/courses/cs111-01/handouts/lab11 into your cs111 directory.

Copy the files from your lab10 directory into the lab11 directory so that you can extend your FaceSpace program in this lab.

How Big Is My Program? (10 pts)

You've been writing code for 11 weeks (or so), and the programs have slowly gotten larger. Last week's lab was the largest yet.

Objective: Programming in Python

Extending the Social Network Program

If you haven't completed the Lab 10 social network program and you don't expect to finish it, you can use my solution, which is in the /csdept/local/courses/cs111-01/handouts/lab11/solution/ You can also compare your solution to mine.

Add a key function to SocialNetwork module (10 pts)

Create a function that you will later use to sort a list of Person objects by their names--lowercased. We saw an example of creating and using a key function in the Card class on Friday. Your function should take as a parameter a Person object and return the Person's name, lowercased.

As always, test your function.

Adding Search Functionality to your SocialNetwork class (30 pts)

As discussed in class, you will update your SocialNetwork class to include a method that finds all the people that have a certain name. The method will take as a parameter the name to search for and returns a list of people who have that name. (Note, the method does not take as a parameter the list of Person objects. Where should that list come from?) Your method should:

What are good test cases for this method? I have some duplicate names in the hollywood.txt file. You may need to update the test files so that they have more than one person with the same name.

Your user interface will be responsible for printing out the people that belong to the network or printing out a message if no people match.

Recommended Development Process:

By now, you should know how to do this yourself--we've been breaking down larger problems into small problems all term.

  1. Implement the method to just find one person with the network, exactly, and return that Person; test.
  2. Modify the method to handle the lowercase name; test.
  3. Modify the method to find *all* Persons with the name, lowercased; test.

Adding Options to your FaceSpace User Interface Program (15 pts)

Add an option that allows the user to find all the people that belong to some network. This shouldn't be too difficult if you've organized your code well.

Example Run: 

ID     Name                      Num Friends
---------------------------------------------
1      John Doe                            3         
2      Jane Smith                          2         
3      James Jones                         2         
4      Henry VIII                          2         
5      Lady MacBeth                        1
6      John Doe                            2

Select one of the following options:
        (D)isplay the social network
        (V)iew a person in the social network
        (S)earch for people in the social network
        Add (P)eople to the social network from a file
        Add (C)onnections to the social network from a file
        Add a (U)ser to the social network
        Add a pair of (F)riends to the social network
        E(X)port the social network
        (Q)uit the program

Which option do you want? s
What is the name of the person you want to find? jane smith

1: Jane Smith has 2 friends

...

Which option do you want? s

What is the name of the person you want to find? jOhN DoE

1: John Doe has 3 friends
6: John Doe has 2 friends

...

Which option do you want? s

What is the name of the person you want to find? Lady
No person named Lady found.

Demonstrate Your Program

Demonstrate that your program works in IDLE (just the new functionality) and save the output in an appropriately named ".out" file.

Linux: How Much Code Did You Add?

Run the wc command again. This time, view the size of the .py files in your lab11 directory. Add the output from this command to your mywc.txt file using the >> operator. An example of running wc from your lab11 directory is
wc -l *.py >> mywc.txt

Now, when you view your mywc.txt file, you should be able to compute how many more lines of code you added to your files for this part of the project. Document this difference in comments in social.py.

Working with 2D Lists

For each of the following problems, create a new Python script.

After you've developed a correct solution to each program, restart IDLE or close and reopen the IDLE "shell" by running the program again (using F5), demonstrate that the program works using several good test cases, and save the output to a file named lab11.x.out, where x is the problem number.

  1. (10 pts) Create a 2D list that looks like: 
    [ [0,1,2], [1,3,5], [2,5,8] ]

    Simply print the list; do not worry about formatting yet.

    To make each row, you can either use the range function or append to a list, but do not create the list by typing twod=[ [0,1,2], [1,3,5], [2,5,8] ]

  2. (10 pts) Copy the previous program for this program. Add a function that takes a two-dimensional list as a parameter and prints that list so that it looks like the below format. Test on the list you created in the last program. However, your function should properly handle any two-dimensional list. 
    0 1 2
1 3 5
2 5 8
  3. (15 pts) If you haven't already, copy all the .py files (connectfour.py and csplot.py) from /csdept/local/courses/cs111-01/handouts/lab11.
    1. Open up connectfour.py and look at the ConnectFour class. Familiarize yourself with its attributes and how other methods we discussed are implemented.
    2. Uncomment the makeMove method and its docstring comment and implement the method. Adhere to the method's comment description when implementing the method.
    3. Uncomment the code in the play method, as described in the code. Run connectfour.py to test your game.

      4. You should only have to modify connectfour.py--not csplot.py.

    You have to hit Control-C in the terminal to kill the game. Attempting to close the window does not work.

    You won't submit any output from this program.

Extra Credit: ConnectFour

Implement the _isDraw (up to 5 pts) or_isWon methods (up to 10 pts) of the ConnectFour class. You can receive partial credit.

Alternatively, you can improve the _computerMakeMove method that chooses the "best" column to place the checker (up to 10 pts). A naive first approach (which is currently implemented) is to randomly pick a column. A more sophisticated approach is to assign a score to each column that says how "good" a column is for you and select the column with the highest score. What properties would make the column's score increase?

Finishing up: What to turn in for this lab

  1. Copy your lab11 directory into your turnin directory.
  2. IDLE and jEdit may create backup files with the "~" extension. Delete these files from your lab directory to save paper when you print.
  3. Move csplot.py into the parent directory. (This is a large file that you don't want to print out.)
  4. Remove any .pyc files from the directory; otherwise, you'll get an error when creating the output file.

Labs are due at the beginning of Friday's class. You should hand in the printed copy at the beginning of class, and the electronic version should be in the turnin directory before 2:25 p.m. on Friday.

Ask well before the deadline if you need help turning in your assignment!

Grading (100 pts)