# List Assertions

In this notebook, you'll learn how to use most used List assertion functions. Below are these functions:

assert_list_variable_equals_variable(student_variable_name, expected_variable_name, delete_afterwards=True): Checks that the student's list in student_variable_name matches the list in expected_variable_name.
assert_list_variable_equals_json(student_variable_name, json_file_name): Checks that the student's list in student_variable_name matches the list contained in the solution JSON file named json_file_name.
assert_list_variable_equals_pickle(student_variable_name, pickle_file_name): Checks that the student's list in student_variable_name matches the list contained in the solution pickle file named pickle_file_name.

Load the utils.py file to use the assertion functions.

exec(open("utils.py").read())

# Student Data for Activities

In the activities, we'll use the below student data. Format of the data is name, marks, age, grade, subject.

There are total 500 students in the list, but we are showing only a few here.

# Import the data from the text file into a list
student_list = [['Gabriel', '53', '18', 'D', 'English'],
                ['Nora', '79', '18', 'F', 'Math'],
                ['Luna', '2', '18', 'A', 'English'],
                ['Anthony', '76', '18', 'A', 'Math'],
                ['Logan', '56', '17', 'D', 'History'],
                ['Luna', '25', '18', 'E', 'Geography'],
                ['Daniel', '29', '18', 'C', 'History'],
                ['Sarah', '92', '17', 'B', 'History'],
                ['Victoria', '91', '17', 'D', 'History'],
                ['Zoe', '47', '18', 'E', 'Geography']
                ...
                ]

# Activities

# 1. Put the students from the index 98 to 104 into the list `best_students`

Create a list select_student from the original list(student_list), starting at index 98 up to, but not including, index 104.

Make sure to not change the order of the students.

Expected output:

[['Luna', '25', '18', 'E', 'Geography'],
 ['Daniel', '29', '18', 'C', 'History'],
 ['Sarah', '92', '17', 'B', 'History'],
 ['Victoria', '91', '17', 'D', 'History'],
 ['Zoe', '47', '18', 'E', 'Geography'],
 ...
]

select_student = ...

Solutions:

select_student = student_list[98:104]
select_student

As we can see the expected output is a list of list which is small(only 6 students), so we use assert_list_variable_equals_variable() function to assert the solution with the student list.

Assertion:

expected_output = [['Luna', '25', '18', 'E', 'Geography'],
 ['Daniel', '29', '18', 'C', 'History'],
 ['Sarah', '92', '17', 'B', 'History'],
 ['Victoria', '91', '17', 'D', 'History'],
 ['Zoe', '47', '18', 'E', 'Geography'],
 ['Ava', '18', 'A', 'Art']]

assert_list_variable_equals_variable('select_student', 'expected_output')

# 2. Get the ages of each student and store it in the list `students_age`

Convert the ages into int as currently they are type str (string).

Loop through the list student_list, access the age, cast it to int, and append it to the new list variable students_age.

students_age = ...

Solutions:

students_age = []
for student in student_list:
    student_age = int(student[2])
    students_age.append(student_age)

students_age

As the expected output is a list of integers containing total of 500 students and it is a large list, so we use assert_list_variable_equals_json() function to assert the solution with the student list.

This is how we can save the expected output in a json file:

# save json file
import json
with open('activity_solutions_files/solution_03.json', 'w') as f:
    json.dump(students_age, f)

Assertion:

# new assertions
assert_list_variable_equals_json("students_age", "solution_03.json")

# 4. Separate all `A` graders and all `B` graders from the list `student_list`.

Create two lists a_graders and b_graders with the name, age, grade, and favorite subject of the students. Put students with A grades to the list a_graders and students with B graders to the list b_graders

Expected output for a_graders:

[['Luna', '18', 'A', 'English'],
 ['Anthony', '18', 'A', 'Math'],
 ['Bella', '17', 'A', 'History'],
 ['Lucy', '17', 'A', 'History'],
 ['Brooklyn', '18', 'A', 'History'],
 ['Ava', '18', 'A', 'Art'],
 ['Riley', '17', 'A', 'Math'],
 ...
]

a_graders = ...
b_graders = ...

Solutions:

a_graders = []
b_graders = []

for student in student_list:
    if student[3]=='A':
        student_name = student[0]
        student_age = student[2]
        student_grade = student[3]
        student_subject = student[4]
        a_graders.append([student_name,student_age,student_grade,student_subject])
    if student[3]=='B':
        student_name = student[0]
        student_age = student[2]
        student_grade = student[3]
        student_subject = student[4]
        b_graders.append([student_name,student_age,student_grade, student_subject])

print(f"len a {len(a_graders)}, len b: {len(b_graders)}")

We use assert_list_variable_equals_json() function to assert the solution with the student list as the expected output is a list of list which is is quite large.

Here, we have two expected outputs, so we save them in two different json files and then use assert_list_variable_equals_json() function to assert the solution with the student list.

# save json file
import json
with open('activity_solutions_files/solution_04_a.json', 'w') as f:
    json.dump(a_graders, f)

with open('activity_solutions_files/solution_04_b.json', 'w') as f:
    json.dump(b_graders, f)

Assertions:

# new assertions
assert_list_variable_equals_json("a_graders", "solution_04_a.json")
assert_list_variable_equals_json("b_graders", "solution_04_b.json")

# 4. Convert the `student_list` into list of tuples.

Given the list student_list is a list of lists. Convert it into a list of tuples and store it in the variable student_list_tuple.

Expected output:

[('Luna', '18', 'A', 'English'),
 ('Anthony', '18', 'A', 'Math'),
 ('Bella', '17', 'A', 'History'),
 ('Lucy', '17', 'A', 'History'),
 ('Brooklyn', '18', 'A', 'History'),
 ('Ava', '18', 'A', 'Art'),
 ('Riley', '17', 'A', 'Math'),
 ...
]

This is just a simple conversion from list of lists to list of tuples. Expected output is different from above example list of tuples.

# Try your code here
student_list_tuple = ...

Solution:

student_list_tuple = []

for student in student_list:
    student_list_tuple.append(tuple(student))
    
student_list_tuple[:5]

As the expected output is a list of tuples which is small, so we use assert_list_variable_equals_pickle() function to assert the solution with the student list as JSON can't save tuples.

This is how we can save the expected output in a pickle file:

# save in a pickle file
import pickle

with open('activity_solutions_files/solution_06.pkl', 'wb') as f:
    pickle.dump(student_list_tuple, f)

Assertions:

# new assertions
assert_list_variable_equals_pickle("student_list_tuple", "solution_06.pkl")

# List Assertions

# Student Data for Activities

# Activities

# 1. Put the students from the index 98 to 104 into the list best_students

# 2. Get the ages of each student and store it in the list students_age

# 4. Separate all A graders and all B graders from the list student_list.

# 4. Convert the student_list into list of tuples.

# 1. Put the students from the index 98 to 104 into the list `best_students`

# 2. Get the ages of each student and store it in the list `students_age`

# 4. Separate all `A` graders and all `B` graders from the list `student_list`.

# 4. Convert the `student_list` into list of tuples.