Exception handling: during console/keyboard input and as well as during file
output
Introduction:
Write a program that simulates the life of a student in CPSC 231
(as shown in Figure 1). The simulated world will be
represented by a 2D Python list of single character strings. A student 'S'
can either choose to maximize his/her fun times 'f'
during the term or the person can choose to expend time working 'w'
in order to maximize the term grade point (GPA) and letter graded
awarded. In this simulation there is not only a direct but a perfect
correlation between time spent working and the grade awarded.1
Like a semester in "real life" there is only a finite amount of
time during a term and the simulation will run for a maximum of 13 turns
(weeks). Each time that the user is prompted to move the student (or if
the choice is given up) a time unit will be expended.
The initial starting positions will be read in from a text file whose name is
specified as the program is started. The student's 'score' (fun and grade points
earned along with the term letter grade) is saved to another text file 'scores.txt'.
Only one set of scores are retained, each time that the simulation runs
previous scores are overwritten.
Figure 1: The simulated world
To add a level of uncertainty and challenge to the simulation two random
events may occur. "The Pavol" may manifest itself ethereally (no
physical appearance) and cause time to appear to
stand still for a single week (the time expended by the user's actions won't actually increment
time). The Pavol will affect time in the simulation but the Pavol itself doesn't
physically appear in the simulation. Also the dread "Taminator" may appear. Unlike The Pavol the Taminator
will physically appear. The Taminator can sense the location of a student
and it will move towards the person. At maximum speed the Taminator travels at twice
the speed of a student. When the Taminator has caught a student, the passage of
time will accelerate (3 time units expended instead of 1). Fortunately (and
ironically) the time that a Taminator appears is limited (3 'normal' weeks
which is not counting the acceleration of time that it causes). Both The Pavol
and the Taminator can appear multiple times during the simulation. But only one
'event' or the other will occur: if The Pavol has already appeared then the
Taminator won't appear. Or if the Taminator has appeared and hasn't yet vanished
then The Pavol won't make a manifestation.
Details:
In order to get credit for some features other features must have been
implemented first (e.g. to get credit for moving on top of fun and work
points, the ability to move the student has to be working first). Some of the
most obvious prerequisites have been listed in the description below.
Initialization
The program starts by reading the starting positions from a
text file whose name will be specified by the user at run time. You can either
use the functions provided in the starting program or you can write your own.
In
order to get any credit for this assignment your program must be able to read
the information from file. This will not only allow your marker to more quickly
evaluate the results, but will also make it easier for you to run tests.
Options for using the pre-written file input functions.
There is no advantage to using one vs. another. One approach splits the task
into two functions to make things easier to interpret by students while the
other combines the task into one function. Both functions return a list that has
been initialized from the data in the specified file.
1) Option I, using a single function:
createListFileRead(). The function creates a new
empty row with each iteration of the outer loop. The inner loop successively
appends new data (read in from file) onto the new row.
2) Option II, using two functions:
initialize() and readFromFile().
The first function creates the list row by row and then appends a default value
for each element '!' to the end of each row. The
second function performs all of the file input. Line by the line the text from
the input file is read in and the along that line each character is used to set
each element of the list.
The input file will specify the starting positions for most
of the main elements in the simulation:
'w' represents an
opportunity to work on coding a Python program.
'f' represent an
opportunity for the student to have a fun experience.
'S' represents the
starting position of the student.
Spaces represent empty parts of the simulation - since
your life is just about school and fun everything else is just a void right?
;)
You can assume that the Taminator 'T'
will never be read in from an input file it has to be randomly generated as the
game runs (or manually invoked by the user). And as mentioned The Pavol doesn't
actually take physical form so it also never appears in the input file.
Another requirement to get any credit for your assignment is
that the display of
the grid must be done using the display() function
provided or you must write an equivalent function yourself. This grid
is required because it makes the display of world easier to read and interpret
for both you and the marker.
The simulation runs for 13 weeks (turns). A
turn is broken into parts or 'sub-turns' which occur in the following order:
Prompt the player for movement and determine the effects of movement
Determine if The Pavol appears (and account for time appearing to stand
still)
Determine if the Taminator appears
Prompting for movement:
The player can move to any adjacent location that is not currently
occupied by the Taminator. The movement options will be represented by a 9
point directional computer keypad grid (Figure 2).
Figure 2: Movement menu
Each direction matches a cardinal compass direction (N=8, W=4, E=6, S = 2)
or inter-cardinal compass direction (NW=7, SW=1, NE=9, SE=3). Selecting 5
doesn't move the student but still causes a turn to pass. Unlike previous
assignments: Your program should not produce a run time error if
an invalid input type is entered (i.e. a string instead of a number).
Instead exception handling should be employed which displays a useful error
message and continues prompting until a valid value has been received.
The program should also continually re-prompt if a value of less than zero
or greater than nine has been entered. Entering a value from 1 - 9 (save for
5) will result in the student moving in that direction and a turn being
expended. If an attempt is made to move the student outside the bounds of
the simulation or onto the Taminator then another useful error message
should appear. Time will not pass if an invalid value or if an attempt is
made to move the student to an invalid location (outside or Taminator
occupied). Entering a zero will result in the secret cheat menu appearing:
Cheat menu options
(t)oggle debug mode off
(m)ake the Taminator appear
(p)avol manifests itself
(q)uit cheat menu
The user will be repeatedly prompted for a selection so long as an option
other than one of the ones above have been selected. Toggle debug mode flips
the state of the global debug flag between True and False. When the flag is
set to True, debugging messages will appear. Their exact content is up to
you but generally the message should be visually distinct (e.g. capitals,
surrounded with angled brackets, indented etc) and specify the function that
where the debugging message appears e.g. <<move()
Taminator original location (4,5)>>. Selecting the option to make the
Taminator appear will allow the user to select a (row, column) location. A
location outside the list or one that one is currently occupied by the
student will result in a re-prompting until a valid location is entered.
You are not required to type check the Taminator location as you did with the
direction of movement (moving the student). Once a valid location has
been entered, the Taminator will start moving towards the student (more
information on the Taminator event).
Manifesting the Pavol will result in time suspending itself. Trying to get
the Taminator or Pavol to appear via the cheat menu when the Taminator
has already appeared should result in an error message and the program
prompting the user for a cheat menu option again. (Since the Pavol only
appears for a turn and the check for the
Pavol's appearance occurs after the player's turn it won't be possible
to try to invoke either the Pavol or Taminator when the Pavol has appeared).
Selecting a valid cheat menu option (even the option to quit) will result in
a time unit being expended as if the user had selected a valid movement
option. Entering an invalid option will not cause time to advance (again as
was the case with the movement menu).
Moving the student onto the special objects: as mentioned the student cannot be moved outside of
the simulation nor can the student being moved onto a location occupied by
the Taminator. (No one can 'grapple' the Taminator!) Moving onto the a location with an opportunity for fun 'f'
will increase the "fun points" by 1. Moving onto the a location with an
opportunity for work 'w' will increase the
grade point by 1. In order to get credit for these features, the
program must actually allow the user to move the student. The work or fun opportunity is expended by the student and
doesn't reappear in the location after the student moves. The current number
of fun points and grade points (but not letter grade) awarded is displayed at the start of each
turn:
Figure 3: display of fun and
grade points
After moving the student, the simulation will check for the possible
occurrence of two events in the
following order:
Running The Pavol event (you will only
receive credit for this feature if the appropriate option in the cheat menu
has been fully and correctly implemented and time must be properly tracked in order to
get credit for this feature):
There's a 10% chance of this event
occurring during a particular turn. This event only last for a single turn and it won't occur if the Taminator event is already in progress.
The Pavol doesn't actually physically appear but it only affects the passage of
time. The student gets an additional turn (normally
the game will advance by one turn but the appearance of The Pavol causes
time to roll back by one. So the appearance of The Pavol and time moving
forward will cancel each other out..."time appears to stand still when
you are lucky enough to be in the positive presence of "The Pavol."
Before The Pavol appears (turn 1):
Figure 4: The 'turn' when The
Pavol makes a manifestation
After the Pavol appears (the student
collected a fun point by moving NW and consuming some 'fun' but it's still turn 1)
Figure 5: The turn after The
Pavol has departed
The next turn
The Pavol will disappear and time resumes it's normal course (unless the
Pavol appears during the next turn as well). The Pavol can
appear multiple times during a simulation but as mentioned it won't appear
at the same time as the Taminator.
Running the Taminator event
(you will only receive credit for this feature if the appropriate option in the cheat menu
has been fully and correctly implemented, time must be correctly tracked in
the simulation).
If the Pavol hasn't
appeared during a turn, the
simulation checks against a 25% probability that the Taminator will appear. If
that is the case the Taminator will randomly appear at a location that is
not currently occupied by the student. If it materializes on top of a work
or fun opportunity both are destroyed by the Taminator (the object won't
reappear after the Taminator has moved). Immediately after appearing the Taminator will start moving
towards the student at a maximum speed of 2 rows and 2 columns. The
Taminator will continue moving towards the student until either it's
adjacent to the student or it's current time has come to an end.
The Taminator will only move to an adjacent position to the student. It
won't move past the student by moving 2 full units (i.e. if it's already
close to the student) nor will it move onto the location that is currently
occupied by the student. If the Taminator is already in "close range:" the
student it will slow down to 1 movement unit. And the Taminator is 'smart'
enough so it can move faster along the row or column (only) if the distance
is greater along that dimension only (see Figure 8). The Taminator will
appear for 3 turns (includes the turn in which the Taminator first appears)
and then it will vanish. Whenever the Taminator has caught up to the student
(adjacent) the program must advanced time by an additional 2 turns (plus the
normal passage of 1 turn = 3 turns passing for each turn that the Taminator
is adjacent). It's your choice if time stops at 13 turns or goes beyond that
but the simulation must stop at 13 (or more) weeks. While the Taminator is moving it becomes mystically
incorporeal like The Pavol. Consequently any work and fun opportunities in
it's path the student won't be destroyed. However once it stops moving it
becomes solid again and a work or fun opportunity at the destination (where
it stops) is destroyed.
The Taminator is by far the most complicated program feature so a more
detailed explanation is provided. In this example the Taminator is invoked
during Turn 1 via the cheat menu
(Figure 6). During Turn 1 the program counts off 1 time unit out of the three units that
the Taminator will appear. Also notice that invoking of the cheat menu
causes one time unit to pass.
Figure 6: Initial appearance
of the Taminator
The next turn shows the Taminator has moved 2 rows and 2 columns towards
the student during the last turn. (The Taminator reacts quickly and can
immediately start moving). The movement was shown to the user only after the
user selected a movement option for the student. Only one time unit has passed in the game because
the student has not yet been caught. The program also counts that the Taminator has appeared for 2 turns now. Finally notice that the work
opportunity (1,1) that was in direct path (but not the final destination) from the Taminator to the student
still remains intact (Location (1,1) in Figure 7).
Figure 7: The Taminator first
appears
The Taminator moves only 1 row the next turn because this is
all the distance that is needed in order to enter an adjacent position to
the student. (It could move right by 1 column and still be adjacent but the
Taminator is efficient in its movement). Now that the student has been caught time advances by 3 time
units this turn. Notice that the fun opportunity that was located at the new
destination of the Taminator (3,2) is now destroyed (Figure 8).
Figure 8: The Taminator
catches the student
The Taminator has made it's appearance for 3 time units and will vanish
during the next turn (shown after the student moves). Notice also that fun
opportunity at (3,2) has not re-appeared (Figure 9).
Figure 9: The time of the
Taminator has passed
There can only be one Taminator appearing at a time. If the program
already randomly generated a Taminator, then the cheat menu won't allow the player to
invoke another. As mentioned a suitable error message should be displayed instead.
(An error message should also appear if the user manually invoked the
Taminator and tries to invoke it again before it has vanished). Time
will pass even though the Taminator couldn't be invoked (actually it
couldn't be re-invoked) because the cheat menu was summoned. In a similar fashion the
program shouldn't check for a new random Taminator event if the Taminator is
still making it's appearance whether it was generated randomly or by the
user via the cheat menu.
End of the simulation:
When the game is over the game (all weeks have elapsed
naturally or in accelerated fashion due to the appearance of the Taminator) the
usual statistics will be
displayed onscreen (but also the letter grade should be displayed since the
final result can be determined). That information should be saved to an
output file, in this case the same name 'stats.txt'
will be used each time to make it consistent and easier for your marker. Exception
handling should be employed to deal with any file output problems during the
save. Specific
formatting isn't required for the scores file but the information should be
presented in a reasonably neat and legible fashion. (Use format specifiers or
escape codes as needed). Mapping of grade points to
a letter is largely as expected: 0 grade point = F, 1 grade point = D, 2
grade points = C, 3 grade points = B, 4 or more grade points = A.
D2L configuration:
Multiple submissions are possible for each assignment: You can and should
submit many times before the due date. For this assignment D2L will keep
older versions of your submissions.
Important!
Multiple files can be submitted for each assignment. I am allowing you to
submit multiple files for each assignment so don't archive/compress
multiple files using a utility such as zip. However, this means that
TAs will only mark the latest versions of each file submitted via D2L.
Even if the version of a document that you want marked has been uploaded
into D2L if it isn't the latest version then you will only get marks for the
latest version. (It's unfair to have the TAs check versions or to remark
assignments because marking is enough work as-is).
Marking
Assignments will be marked by your tutorial instructor (the "Teaching
Assistant" or "TA"). When you have questions about marking this is the first
person that you should be directing your questions towards. If you still
have question after you have talked to your TA, then you can talk to your
course (lecture) instructor.
As well as being marked
on whether "your program works" you will also be marked on non-functional
requirements such as style and documentation. Consequently this assignment
will include a separate [marking
checklist]. Besides seeing your grade point in D2L you can also see
the detailed feedback that your TA will enter for each student. You can
access the grading sheet in D2L under
Assessments->Dropbox and then clicking on the appropriate assignment
link. If you still cannot find the grading sheet then here is a [help
link]
Points to keep in mind:
Due time:
All assignments are due at 5 PM on the
due dates
listed on the course web page. Late assignments or components of
assignments will not be accepted for marking without approval for an
extension beforehand. Alternate submission mechanisms (non exhaustive list
of examples: email, uploads to cloud-based systems such as Google drive,
time-stamps, TA memories) cannot be used as alternatives if you have
forgotten to submit work or otherwise have not properly submitted into D2L.
Only files submitted into D2L by the due date is what will be
marked, everything else will be awarded no credit.
Extensions
may be granted for reasonable cases by the course instructor with the
receipt of the appropriate documentation (e.g., a doctor's note). Typical
examples of reasonable cases for an extension include: illness or a death in
the family. Example cases where extensions will not be granted include
situations that are typical of student life: having multiple due dates, work
commitments etc. Tutorial instructors (TA's) will not be able to provide
extension on their own and must receive permission from the course
instructor first.
Method of submission:
You are to submit your assignment using D2L [help
link].
Make sure that you [check
the contents of your submitted files]
(e.g., is the file okay or was it corrupted, is it the correct version
etc.). It's your responsibility to do this! (Make sure that you submit your
assignment with enough time before it comes due for you to do a check).
Identifying information:
All assignments should include contact information (full name, student ID
number and tutorial section) at the very top of your program in the class
where the 'main()'
method resides (starting execution point). (Note other documentation is also
required for most assignments).
Collaboration:
Assignments must reflect individual work;
group work is not allowed in this class nor can you copy the work of
others. For more detailed information as to what constitutes academic
misconduct (i.e., cheating) for this course please read the following [link].
Execution:
programs must run on the computer science network running Python 3.x. If you
write you code in the lab and work remotely using a remote login program
such as Putty or SSH. If you choose to install Python on your own computer
then it is your responsibility to ensure that your program will run properly
here. It's not recommended that you use an IDE for writing your programs but
if you use one then make sure that you submit your program in the form of
text ".py" file or files.
Use of pre-created Python
libraries:
unless otherwise told you are to write the code yourself and not use any
pre-created functions. For this assignment the usual acceptable functions
include: print(),
input()
and the 'conversion' functions such as int(),
float(),
str().
Look at the particular assignment description for a list of other classes
that you are allowed to use and still get credit in an assignment
submission.
Assignment resources:
You can find sample input files (you are highly encouraged to make your
own as well) under:
/home/231/assignments/assignment4/inputs [Shortcut]
The starting code for the assignment can be found under:
/home/231/assignments/assignment4/code
[Shortcut]
