CPSC 170 A

Lecture 12 - Test

---

If you do not currently have a directory for tests, create one in your cs170 directory, and also create a directory for test1

$ mkdir ~/cs170/tests
$ mkdir ~/cs170/tests/test1
$ cd ~/cs170/test/test1

---

This portion of the test is worth 50 total points. You may reference any files within your directory. You may only access the Python documentation website and the tkinter documentation website. NO OTHER WEBSITES ARE PERMITTED. As usual, you are not allowed to directly copy any code from the Internet or another individual without citation. You should also follow all coding standards discussed thus far.

---

Question 8

In a file called question_8.py, create a program that creates a 400 × 400 window, and fills it with a target seen below. This target is centered in the window, and each circle is 75 pixels smaller than the enclosing circle.

(10 points)

Question 9

In a file called question_9.py, define a function called compute_sums. This function should take an integer as a parameter, and compute the sum of the numbers in the range [0, n].

Define a NegativeInput class, that represents an Exception that you are creating. Your compute_sums function should raise this exception if it is provided with a value less than 0.

Write driver program that prompts the user for an integer, and attempts to call compute_sums with the input. Your program should terminate ungracefully if you have to raise the NegativeInput exception. If your code might cause any other exceptions, you should put appropriate exception handlers to handle those exceptions.

>>> compute_sums(2)
3
>>> compute_sums(7)
28
>>> compute_sums(-1)
...
__main__.NegativeInput: That wasn't a positive number!
$ python3 question_9.py
What number do you want to compute the sum of? 5
15
$ python3 question_9.py
What number do you want to compute the sum of? -5
...
__main__.NegativeInput: That wasn't a positive number!
$ python3 question_9.py
What number do you want to compute the sum of? asdf
That wasn't a number.
$

(10 points)

Question 10

In a file called questions_10_11.py, create a class called Simulator. This class should have attributes PC, R1, and R2. All three attributes should be integers, and should be defaulted to the value 0. This class should have methods called add and sub, which performs the specified operations on R1 and R2 (in that order, so R1 - R2), and stores the result in attribute R1. Each operation should increment the PC attribute by 1. You should also provide methods called set_R1 and set_R2, which allow the values of R1 and R2 to be set, respectively.

  >>> my_sim = Simulator()
  >>> my_sim.set_R1(3)
  >>> my_sim.set_R2(4)
  >>> my_sim.add()
  >>> print(my_sim.R1)
  7
  >>> my_sim.sub()
  >>> print(my_sim.R1)
  3
  

(15 points)

Question 11

In the same file as above, create a class called AdvSimulator, which inherits your above definition of Simulator. This should add two additional attributes: R3 and R4. These should also be integers, but their values should be provied to the constructor. You should define appropriate methods for setting these registers as well. You need to define methods to copy the value from R3 or R4 into R2. These methods named following the template copy_R#_to_R2. You also need to add two additional methods: mul and div, which computes the product and quotient (integer!) of R1 and R2 (respectively), and stores them in the R1 attribute.

  >>> my_adv_sim = AdvSimulator(1, 2)
  >>> my_adv_sim.set_R3(2)
  >>> my_adv_sim.set_R1(3)
  >>> my_adv_sim.set_R2(4)
  >>> my_adv_sim.add()
  >>> print(my_adv_sim.R1)
  7
  >>> my_adv_sim.sub()
  >>> print(my_adv_sim.R1)
  3
  >>> my_adv_sim.copy_R4_to_R2()
  >>> print(my_adv_sim.R2)
  2
  >>> my_adv_sim.mul()
  >>> print(my_adv_sim.R1)
  6
  >>> my_adv_sim.div()
  >>> print(my_adv_sim.R1)
  3
  

(15 points)

 

---

---

Submission

When you have finished, create a tar file of your test1 directory. To create a tar file, execute the following commands:

cd ~/cs170/tests
tar czvf test1.tgz test1/

To submit your activity, go to cseval.roanoke.edu. You should see an available assignment called Test 1. Make sure you include a header listing the authors of the file.

---

Last modified: Fri Feb 7 13:44:28 EST 2014