A. (100 points) Othello
This examination consists of designing and writing a single well-structured Python program that must be
committed and pushed to your remote GitHub examination repository prior to the deadline. Note that your
program must be named othello.py (all lower-case).
Late submissions will not be accepted and will result in a zero score for the exam.
TA help for this examination will not be provided. If you have clarification questions, they must be addressed
to the graduate TA for the class.
The total point value will be awarded for solutions that are complete, correct, and well structured. A “well
structured” program entails good design that employs meaningful functional decomposition, appropriate
comments and general readability (descriptive names for variables and procedures, appropriate use of blank
space, etc.) If you are not sure what this means, review the “well-structured” program requirements provided in
Note that your work will be graded using, and must function correctly with, the current version of Python 3 on
CSE Labs UNIX machines. If you complete this programming exam using a different system, it is your
responsibility to ensure it works on CSELabs machines prior to submitting it.
The rubric includes the following specific (accumulative) point deductions:
• Missing academic integrity pledge -100 points
• Syntax errors -50 to -100 points
• Misnamed source file or incorrect repository -25 points
• Use of global variables -25 points
• Missing main program function -25 points
Examination files must be submitted to GitHub using your remote exam repository. Exam repositories have
already been created for each registered student and are named using the string exam- followed by your X500
userID (e.g., exam-smit1234). You must first clone your exam repository in your local home directory
before submitting the materials for this exam. If you are having difficulty, consult the second Lab from earlier in
the semester or the GitHub tutorial on the class webpage. If your exam repository is missing or something is
amiss, please contact the graduate TA. DO NOT SUBMIT YOUR EXAM FILES TO YOUR LAB/EXERCISE
The modern board game, Othello, is a commercially produced version of a game that originated in the 19th
century called ‘Reversi’. It’s an interesting 2-player game of strategy played on an 8×8 grid in which each player
places tokens on the board in order to cover more grid cells than their opponent. Each token is a two-sided disk
with white on one side and black on the other. The basic premise of the game is that as each player plays a
token of his/her color (white or black), they ‘flip’ over all the intermediate tokens of their opponent. The game
ends when all the grid cells have been covered with tokens, or no allowable move can be made.
Read the following Wikipedia description of the game:
The following website has an interactive version that you can play. You should try it to make sure you are
comfortable with how the game is played:
Using Turtle graphics, write a well-structured Python program named othello.py that will play an
interactive game of Othello. Your program will pit a human player against the computer.
Your program must do the following:
• Include the academic integrity pledge in the program source code (details below)
• Use turtle graphics to implement the graphical interface (set the turtle speed to 0 in order to speed
• The graphical display must include numeric row and column number “headers” to assist the human
player in determining what to enter.
• Maintain the board state using a 2-dimensional list (matrix) with 8 rows of 8 columns. Each board
location must indicate if it has a black token, a white token or is unoccupied. The upper-left cell is
board location , and the lower right cell is board location .
• The “human” player will play black and the computer will play white. The human player will always go
first. Your program must include a loop that will alternate between soliciting the human player’s move
(row, column) and making the next “computer” play. The game continues until the entire board is
occupied or until either player can no longer make a valid move. The game can also be terminated
prematurely by entering a null-string as input.
• A message should appear when the game ends indicating which player is the winner, along with the
• Avoid using global variables (global constants are perfectly fine). You will need to pass the “board”
matrix as an argument to the various functions that need it.
• Solicit input using the turtle .textinput()function. The input should consist of the row and
column for the next (human) play.
• Include a pure function: selectNextPlay(board) that will be called to get the computer’s next
play. You can be as creative as you wish, however it is acceptable to simply make a random choice
from any of the remaining valid moves.
• Include a pure Boolean function: isValidMove(board,row,col,color) that will return True
if the specified row,column is a “valid” move for the given color and False otherwise. Note that for a
move to be valid, it must satisfy three conditions:
1. It must be unoccupied
2. At least one of its 8 neighbors must be occupied by an opponent’s token (opposite of color)
3. At least one of the straight lines starting from row,col and continuing horizontally, vertically or
diagonally in any direction must start with an opponent’s token and end with a token matching
the color argument.
• Include a pure function: getValidMoves(board,color) that will scan every cell of the
board and return a list of (row,column) tuples that are valid plays for the indicated token color.
• You can find descriptions of the .textinput()and.write()turtle functions (along with all
the Turtle graphics module functions) here: docs.python.org/3/library/turtle.html .
• You may use any built-in Python object class methods (string, list, etc.)
• You may use imported functions and class methods from the turtle, random and math
Academic Integrity Pledge
The first lines of your program must contain the following text (exactly as it appears), replacing the first line
with your full name and X500 ID. If this statement does not appear in your program source, you will receive a
score of zero for the exam.
# I understand this is a graded, individual examination that may not be
# discussed with anyone. I also understand that obtaining solutions or
# partial solutions from outside sources, or discussing
# any aspect of the examination with anyone will result in failing the course.
# I further certify that this program represents my own work. None of it was
# obtained from any source other than material presented as part of the
• You will find this project much easier if you employ the principles of “top-down, functional
decomposition”, as discussed in lecture, and implement your program as a collection of short, simple
• The graphical display is fairly uncomplicated if you set the world coordinates to match the board
(leaving some room for the border) and use the turtle.stamp() method. You simply change the turtle
shape to “square” and “stamp” it at each grid cell location. Then change the turtle shape to “circle” and
“stamp” each token when it is played (in the appropriate color)
• You will find it useful to construct (and use!) a “helper” function that will convert “row, column” board
coordinates to “x, y” turtle coordinates!
• The most complicated aspect of this program is determining the lines of opponent tokens to “flip” when
a move is made (this is also needed to determine if a proposed move is “valid”). One way to do this is to
subtract the corresponding row and column coordinates of the first two cells in a “line” (horizontal,
vertical, diagonal) to obtain a row and column “delta value”. This delta value can be used in an
iteration loop to identify all the cells in that line.
• One of the challenges in this problem is dealing with the grid border. For example, the cell at 
does not have 8 neighbors, it has 3. You might find it useful to construct a helper function that returns a
list of neighbors, given a cell’s row and column. Another useful helper function would return a Boolean
indicating if a particular row, column pair is “inGrid”.
Example Program Output