Description
1. GOALS/OUTCOMES FOR LAB
– To practice using assert
– To be more familiar with type hinting
– To write test function to test your code using Pytest
2. LAB 7 – TASK/INSTRUCTIONS
Task 0: [This will be the same for all labs]: Start your code with comments that include this lab ID, your full
name, email address, and student id as follows:
# Lab 7
# Author: Michael S. Brown
# Email: msb99898@aol.com
# Student ID: 10233030
This lab involves generating several functions. Please read carefully. A video of this lab running is available
here.
This lab has two (2) tasks. You will also need to install Pytest – see course notes.
See the explanation of the lab on the next pages.
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Lab 7 – Writing test cases for code
STARTING CODE LINK: https://www.eecs.yorku.ca/~mbrown/Lab7_start.py
The starting code is also shown here. There are three functions of importance (shown in blue)
import pytest
from typing import List
# Accepts a list of integers
def initializeMinMaxList(myList: List[int]) -> None: # given
myList.sort()
def insertItem(myList: List[int], item: int) -> None: # given
myList.append(item)
myList.sort()
def getMinMax(myList: List[int], minormax: str) -> int: # given — but requires additional assert
assert minormax.upper()==”MAX” or minormax.upper()==”MIN”, “2nd argument must be ‘Min’ or ‘Max’ ”
result: int
if minormax == “MAX”:
result = myList[-1]
del myList[-1]
else:
result = myList[0]
del myList[0]
return result
# Main function is given.
def main():
aList = [10, 11, 99, 1, 55, 100, 34, 88]
print(“Starting List: “, aList)
initializeMinMaxList(aList)
min1 = getMinMax(aList, “MIN”)
print(“1st min: %d” % (min1))
min2 = getMinMax(aList, “MIN”)
print(“2nd min: %d” % (min2))
max1 = getMinMax(aList, “MAX”)
print(“1st max: %d” % (max1))
max2 = getMinMax(aList, “MAX”)
print(“2nd max: %d” % (max2))
print(“Insert %d %d %d %d” % (min1 – 1, min2 – 1, max1 + 1, max2 + 1))
insertItem(aList, min1 – 1)
insertItem(aList, min2 – 1)
insertItem(aList, max1 + 1)
insertItem(aList, max2 + 1)
min1 = getMinMax(aList, “MIN”)
print(“1st min: %d” % (min1))
min2 = getMinMax(aList, “MIN”)
print(“2nd min: %d” % (min2))
max1 = getMinMax(aList, “MAX”)
print(“1st max: %d” % (max1))
max2 = getMinMax(aList, “MAX”)
print(“2nd max: %d” % (max2))
print(“DONE. Please Enter to exit.”)
input()
if __name__ == “__main__”:
main()
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What does the code provided do?
The code provides a set of functions that implements a “minmax list” of integers. There are three functions we will use to with the
minmax list, namely initializeMinMaxList() , insertItem() , and getMinMax().
The minmax-list works as follows.
(1) Assume you have a list of integers.
e.g., x = [20, 99, 88, 1, 100, 0]
(2) Call function initializeMinMaxList( List[int] ) -> None
e.g., initializeMinMaxList(x)
(3) After it has been initialized, you can insert items into the list using insertItem( List[int], int) -> None
e.g., insertItem(x, 10), insertItem(x,-1)
(4) To exact the min or max from the list, call function getMinMax( List[int], str=”MIN” or “MAX”) -> int
minItem = getMinMax( x, “MIN”)
maxItem = getMinMax(x, “MAX”)
The function getMinMax() will return the minimum or maximum item from the list, and delete the item from the list.
getMinMax(List[int], str=”MIN” or “MAX”) has two pre-conditions.
(1) The string must be either “MIN” or “MAX” – if not, the code will raise an assertion error.
(2) The List[int] must not be empty. If it is, the code should raise an assertion error.
See main() to see example usage of the minmaxList functions.
Running the code provided to you will give the following output.
Starting List: [10, 11, 99, 1, 55, 100, 34, 88]
1st min: 1
2nd min: 10
1st max: 100
2nd max: 99
Insert 0 9 101 100
1st min: 0
2nd min: 9
1st max: 101
2nd max: 100
DONE. Type Enter to exit.
See next page for Lab 7’s TASKS
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Lab 7’s TASKs
TASK 1 – Checking Pre-condition for empty list [modify getMinMax() ] (2 points)
Modify the function getMinMax(List[int], str) to include an assert statement to check the pre-condition that the list is not
empty. There is already an assert checking if the str is either “MIN” or “MAX”.
TASK 2 – Test functions for our code. [write five (5) Pytest functions]
Modify the starting code to include the following five (5) test functions for use with Pytest.
These functions should appear at the end of the current code.
Please name your functions exactly as shown below.
(1) def test_getMinMaxCase1():
This function will test a standard use case for our minmaxList.
(a) Create a list with two items that are different.
(b) Call initializeList() with (a).
(c) Use getMinMax() to get the mimimum item. Use an assert statement to check if this is correct.
Error message should be “Min should be x”, where x is the minimum item in the list specified in (a).
(d) Use getMinMax() to get the maximum item. Use an assert statement to check if this is correct.
Error message should be “Max should be x”, where x is the maximum item in the list specified in (a).
(2) def test_getMinMaxCase2():
This function will test an edge case where the list only has a single item.
(a) Create a list with only 1 item, let’s call this item y.
(b) Call initializeList() with (a).
(c) Use getMinMax() to get the mimimum item (which is y). Use an assert statement to check if this is correct.
Error message should be “Min should be y”, where y is the single item in your list in (a).
(d) Use insertItem() to insert the same item y back into the list in (a).
(e) Use getMinMax() to get the maximum item (which is y). Use an assert statement to check if this is correct.
Error message should be “Max should be y”, where y is the maximum item in the list specified in (a).
(3) def test_getMinMaxCase3():
This function will test an edge case where the list starts out empty.
(a) Create an empty list.
(b) Call initializeList() with (a).
(c) Insert an item x into (a) using insertItem().
(d) Insert an item y into (a) using insertItem(). Item y should be larger than x.
(e) Use getMinMax() to get the mimimum item. Use an assert statement to check if this is correct.
Error message should be “Min should be x”, where x is the minimum item inserted into (a).
(f) Use getMinMax() to get the maximum item. Use an assert statement to check if this is correct.
Error message should be “Max should be y”, where y is the maximum item inserted into (a).
(4) def test_getMinMaxRequestError()
This function will test to see if getMinMax() properly causes an assertion error when the string argument is not correct.
(a) Create a list with 3 items.
(b) Call initializeList() with (a).
(c) Call getMinMax() with a, but using “MID” instead of “MIN” or “MAX”. This will cause getMinMax() to raise an AssertionError.
(d) Check if the AssertionError was raised. Assert on this condition, if the condition was not rasie, your error should be:
“Should raise AssertionError!”
Continues on next page.
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(5) def test_getMinMaxEmptyError():
This function will test to see if getMinMax() properly causes an assertion error when the list is empty.
(a) Create an empty list.
(b) Call initializeList() with (a).
(c) Call getMinMax(). If you did Task 1 correctly, this will cause getMinMax() to raise an AssertionError.
(d) Check if the AssertionError was raised. Assert on this condition, if the condition was not rasie, your error should be:
“Should raise AssertionError!”
VERIFYING YOU TEST FUNCTIONS WITH PYTEST
Remember to first install Pytest using the pip command as described in the notes. Now, verify that your test functions work by using
“pytest lab7.py” from PyCharm’s terminal.
To the best of our knowledge, the code provided to you does not have any bugs, so the 5 test should all pass if written correctly.
The expected output would look as follows.
(venv) C:\Users\mbrown\PycharmProjects\pythonProject1>pytest Lab7.py
==================== test session starts ====================
platform win32 — Python 3.8.5, pytest-6.1.2, py-1.9.0, pluggy-0.13.1
rootdir: C:\Users\mbrown\PycharmProjects\pythonProject1
collected 5 items
Lab7.py …..
[100%]
==================== 5 passed in 0.04s ====================
NOTE: You can force a failure of your test cases by commenting out one of the assert statements in the function getMinMax().
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3. GRADING SCHEME (Maximum number of points possible 10)
To get full marks you need to make sure you follow the instructions correctly. The following will be our
grading scheme for the Lab components specified in Section 2 of this document.
Task 0: (0 points, but deduction if you skip this part)
Filename must be “lab7.py” (all lowercase, no spaces)
The Python comments at the beginning of your program must include your name, email, and York
student id (this is important for grading)
If your file name is incorrect, or you do not put in the required information we will deduct -5 points
(Why are we so harsh? Because if you don’t put in your name and student id it can be very difficult for
the TAs to determine whose submission this is.)
Main Tasks :
2 points for Task 1 (adding assert)
8 points for the Task 2 (adding in the test functions)
-No submission – 0 points
-Any submission 1 week after the due date 50% off the total marks
-Any submission 2 weeks after the due date will not be marked and treated as no submission.
See pages below on how to submit your lab code.
MAKE SURE TO SELECT Lab7 with websubmit
Note, if you use the new experimental testing platform it can perform websubmit for you!
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4. SUBMISSIONS (EECS web-submit)
You will submit your lab using the EECS web submit.
Click on the following URL: https://webapp.eecs.yorku.ca/submit
STEP 1 — If you don’t have an EECS account,
click here to use Passport York (everyone
has a passport York account).
If you do have an EECS account, enter here
and go to STEP 3.
STEP 1 — If you don’t have an EECS account,
click here to use Passport York (everyone
has a passport York account).
If you do have an EECS account, enter here
and go to STEP 3.
STEP 1 — If you don’t have an EECS account,
click here to use Passport York (everyone
has a passport York account).
If you do have an EECS account, enter here
and go to STEP 3.
STEP 2 – Enter your passport York
username/password.
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STEP 3 – Select the correct menu option
as follows. Term “F”, Course “1015”,
Assignment “Lab7”.
STEP 3 cont’ – Select your file. The location
in PyCharm may be complicated. I
recommend you save your PyCharm Python
file to your desktop and select from there.
Remember, name your file lab7.py.
STEP 3 cont’ – once you have entered
everything above, click “Submit Files”.
STEP 4 – Confirm that you have entered
everything in correctly. If you make a
mistake here and submit to the wrong
course, or wrong lab, we won’t be able to
tell and will mark your lab as not submitted.
Please double check before clicking OK.
Lab 6
lab7.py
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For more details on websubmit, see EECS department instructions:
https://wiki.eecs.yorku.ca/dept/tdb/services:submit:websubmit
