Unit Test Challenge Question

This challenge question serves two functions: to get more practice writing a function that modifies a list and to practice writing unit tests!

Part 0. Setup.

Write click on your “lessons” folder and select “New Folder”. Your new folder will be titled “CQ05”. Then right click on “CQ05” and select “New File”. Your new file will be called find_max.py. Then, click on “CQ05” and select “New File” again. This file will be called max_test.py. Go ahead and initialize both files with your __author__ variable.

Part 1. find_and_remove_max

In this file, you will write one function definition called find_and_remove_max. The function will have the following behavior:

• It will take a list[int] as input and return an int.
• It will find and return the largest number in the input list.
• It will also remove all instances of the largest number from the input list.
• If the input list is empty, return -1 and don’t modify the input list.

Here is some example behavior:

python
>>> from lessons.CQ05.find_max import find_and_remove_max
>>> a: list[int] = []
>>> find_and_remove_max(a)
-1
>>> a
[]
>>> b: list[int] = [10,9,8,7,10]
>>> find_and_remove_max(b)
10
>>> b
[9, 8, 7]

(Hint: I recommend using a while loop for the part in the function where you are removing the max value.)

Part 2. Unit Tests

Now, in max_test.py, you are going to write unit tests that test find_and_remove_max!

You should write:

• One use case that ensures find_and_remove_max returns the expected value.
• One use case that ensures find_and_remove_max mutates the input in the expected way.
• One edge case that ensures find_and_remove_max returns the correct value in case of an unconventional input.

(Do not copy the use case from the REPL example in Part 1!)

Part 3. Submission

Create a .zip file by running the following command in your terminal:

python -m tools.submission lessons/CQ05

(For this assignment, you’ll have to submit your entire CQ05 folder!)

Then, drag and drop that .zip file into Gradescope!