Lab Assignment #6 Solution

Assignment Objectives




This lab assignment will give you practice with nested lists and nested loops.




Getting Started




Visit Piazza and download the “bare bones” file lab6.py onto your computer. Open lab6.py in PyCharm and fill in the following information at the top:




1. your first and last name as they appear in Blackboard




2. your Net ID (e.g., jsmith)




3. your Stony Brook ID # (e.g., 111999999)




4. the course number (CSE 101)




5. the assignment name and number (Lab #6)




Submit your final lab6.py file to Blackboard by the due date and time. Late work will not be graded. Code that crashes and cannot be graded will earn no credit.










Part I: Student Grade Alert (20 points)




In this part, you will write a function student alert(). The function simulates a simplified student grade alert system, which will evaluate a list of students’ grades, and return their corresponding “alert level” (more on this later).




The function takes only one argument, students, which is a list of lists. Each sub-list contains one particular student’s grades in the form of letter grade strings. Each letter grade has a corresponding integer value as shown below:




Letter Grade
Corresponding Value
’A’
95
’B’
85
’C’
75
’D’
65
’F
55



Example list: [[’A’,’B’,’A’,’F’,’B’], [’A’,’F’], [’F’,’C’,’D’,’A’,’A’], [’F’,’F’]]

Note that the above example list stores the grades for four students.




The function iterates through each student’s sub-list that contains all of his/her grades, then calculates the average grade for that student. Depending on the average grade for that student, a particular character is appended to a list that the function will return:




• If a student’s average grade is less than 70, it is considered a red alert, so the function appends ’R’ to the result list.




• If a student’s average grade is at least 70 but less than 80, it is considered a yellow alert, so the function appends ’Y’ to the result list.




• If a student’s average grade is at least 80, it is considered green alert (safe), so the function appends ’G’ to the result list.




Eventually, the function returns a list of strings that represent the corresponding alert levels for all the students in the students list. For the example list given earlier, the average grades for the four students are 83, 75, 77 and

55, respectively. Therefore, the list returned by the function would be [’G’,’Y’,’Y’,’R’].




Examples:




Function Call
Return Value
student alert([[’D’], [’A’, ’A’, ’C’, ’D’], [’B’],

[’C’, ’F’, ’C’], [’C’, ’A’, ’A’, ’F’, ’F’, ’D’], [’D’, ’D’, ’C’, ’F’, ’B’]])
[’R’, ’G’, ’G’, ’R’,

’Y’, ’R’]
student alert([[’D’], [’D’, ’B’], [’D’, ’C’, ’F’,

’C’, ’A’, ’D’]])
[’R’, ’Y’, ’Y’]
student alert([[’F’], [’D’, ’C’, ’A’, ’B’], [’C’,

’F’, ’C’], [’F’, ’F’], [’C’, ’B’, ’B’, ’A’, ’F’,

’F’], [’B’, ’C’, ’C’, ’C’], [’F’, ’C’, ’B’, ’B’], [’D’, ’B’, ’D’, ’B’, ’D’, ’C’]])
[’R’, ’G’, ’R’, ’R’,

’Y’, ’Y’, ’Y’, ’Y’]
student alert([[’D’, ’F’, ’C’, ’B’], [’C’, ’A’,

’A’, ’F’, ’A’], [’A’, ’F’], [’A’, ’B’], [’A’, ’A’,

’F’, ’A’]])
[’Y’, ’G’, ’Y’, ’G’,

’G’]
student alert([[’D’, ’B’, ’D’, ’F’], [’D’, ’B’,

’D’], [’A’, ’D’], [’D’, ’B’]])
[’R’, ’Y’, ’G’, ’Y’]
student alert([[’A’], [’B’, ’C’, ’A’, ’D’, ’B’,

’A’], [’F’, ’B’, ’C’, ’A’, ’F’, ’B’], [’A’, ’B’,

’F’, ’A’], [’A’, ’C’, ’A’], [’C’, ’B’, ’B’, ’F’,

’F’], [’A’, ’F’], [’D’]])
[’G’, ’G’, ’Y’, ’G’,

’G’, ’Y’, ’Y’, ’R’]
student alert([[’F’, ’B’], [’B’, ’B’, ’D’, ’F’,

’D’], [’D’], [’D’, ’B’, ’C’, ’D’, ’A’], [’A’, ’A’,

’D’, ’F’, ’D’, ’D’], [’A’], [’D’, ’B’], [’C’, ’F’,

’A’, ’B’, ’A’], [’C’, ’A’, ’A’, ’B’, ’A’]])
[’Y’, ’Y’, ’R’, ’Y’,

’Y’, ’G’, ’Y’, ’G’,

’G’]



student alert([[’A’], [’C’, ’A’], [’C’, ’B’, ’C’],

[’C’], [’F’], [’A’], [’B’, ’B’], [’F’, ’C’, ’C’,

’B’, ’F’, ’F’], [’B’, ’A’, ’F’, ’D’, ’D’], [’F’]])
[’G’, ’G’, ’Y’, ’Y’,

’R’, ’G’, ’G’, ’R’,

’Y’, ’R’]
student alert([[’A’, ’A’, ’B’], [’A’, ’C’, ’B’,

’D’, ’B’, ’D’], [’A’]])
[’G’, ’Y’, ’G’]
student alert([[’F’, ’D’, ’B’]])
[’R’]






Part II: Employee Searcher (20 points)




Some Preliminaries




In Python, a tuple is a collection similar to a list in that it is an ordered collection of items. An important difference, however, is that a tuple is immutable – once created, a tuple cannot be changed. Also, tuples are denoted using parentheses instead of square brackets. As with lists, elements of a tuple are accessed using indexing notation.




For example, given the tuple subjects = (’physics’, ’chemistry’, ’biology’), we could ac- cess the elements of the tuple using subjects[0], subjects[1] and subjects[2].




The Function to Write




In this part of the assignment, you will write a function find employee(), which takes three arguments, in this order:




• employees: A list of lists, in which each sub-list contains information about one particular employee.

Inside each sub-list we always find five tuples, wherein each tuple has two values: the first value is a field name, and the second value is the value of that field.




The fields available are listed below. Note that although the five tuples will always exist, their order inside the sub-list may differ from employee to employee.




◦ ’Name’: this string is the employee’s name




◦ ’Age’: this integer is the employee’s age




◦ ’Salary’: this integer is the employee’s salary




◦ ’Experience’: this integer is the years of experience the employee has




◦ ’Level’: this integer is the employee’s rank




An example employees list containing the information about two employees is given below:




employees = [

[(’Name’, ’Tom’), (’Age’, 21), (’Salary’, 1000), (’Experience’, 1), (’Level’, 1)], [(’Experience’, 2), (’Age’, 22), (’Name’, ’Sam’), (’Salary’, 2500), (’Level’, 3)]

]




•search field: this is the particular field you are looking for




•search value: this is the desired value of a field you are looking for




The function searches the employees list and returns a list of employee names whose search field’s value is equal to search value. For example, if search field = ’Level’ and search value = 2, the function would return a list of employee names whose Level is exactly 2.

In brief, the function executes the following algorithm:




create an empty list (e.g., result) to store the names of employees we will return




for each employee in the list of employees:

1. using a for-loop, search the list of tuples of this employee to find the employee’s name (hint: have an if-statement look at index 0 of each tuple to find the tuple that contains ’Name’ so that we can record the employee’s name, which will be at index 1 of

that particular tuple)

2. using a separate for-loop, search the list of tuples of this employee to find the tuple that the search_field argument at index 0

2a. when we find that tuple, check if the value at index 1 of the tuple equals the search_value argument of the function

2b. if so, append the employee’s name to the result list return the result list




Example:




Imagine that employees contained the following data and we had search field = ’Experience’ and

search value = 1:




[ [(’Level’, 1), (’Age’, 25), (’Salary’, 30008), (’Experience’, 5), (’Name’, ’Janice’)], [(’Name’, ’Jose’), (’Level’, 1), (’Salary’, 30011), (’Experience’, 5), (’Age’, 23)], [(’Experience’, 1), (’Age’, 22), (’Name’, ’Chance’), (’Level’, 2), (’Salary’, 30015)], [(’Name’, ’Erminia’), (’Salary’, 30006), (’Experience’, 4), (’Level’, 5), (’Age’, 18)], [(’Salary’, 30014), (’Level’, 4), (’Experience’, 2), (’Name’, ’Wilton’), (’Age’, 19)], [(’Name’, ’Bibi’), (’Age’, 19), (’Salary’, 30008), (’Experience’, 2), (’Level’, 2)], [(’Salary’, 30000), (’Age’, 23), (’Level’, 4), (’Name’, ’Henry’), (’Experience’, 3)], [(’Age’, 18), (’Salary’, 30009), (’Experience’, 3), (’Level’, 1), (’Name’, ’Tyesha’)], [(’Name’, ’Bethany’), (’Age’, 21), (’Salary’, 30002), (’Experience’, 5), (’Level’, 5)], [(’Salary’, 30013), (’Experience’, 3), (’Name’, ’Sofia’), (’Age’, 20), (’Level’, 3)], [(’Name’, ’Tiffany’), (’Level’, 3), (’Salary’, 30007), (’Experience’, 3), (’Age’, 23)], [(’Level’, 2), (’Age’, 20), (’Name’, ’Darryl’), (’Experience’, 3), (’Salary’, 30008)], [(’Level’, 1), (’Experience’, 5), (’Name’, ’Twila’), (’Age’, 23), (’Salary’, 30014)], [(’Salary’, 30014), (’Name’, ’Aleshia’), (’Experience’, 1), (’Age’, 23), (’Level’, 2)], [(’Experience’, 1), (’Name’, ’Armandina’), (’Level’, 4), (’Age’, 21), (’Salary’, 30010)] ]




In this case, the function would return the list [’Chance’, ’Aleshia’, ’Armandina’] because these are the three employess whose ’Experience’ tuple contains the value 1. Note that you may return the list of names in any order you wish.







How to Submit Your Work for Grading




To submit your .py file for grading:




1. Login to Blackboard and locate the course account for CSE 101.




2. Click on “Assignments” in the left-hand menu and find the link for this assignment.

3. Click on the link for this assignment.




4. Click the “Browse My Computer” button and locate the .py file you wish to submit. Submit only that one

.py file.




5. Click the “Submit” button to submit your work for grading.







Oops, I messed up and I need to resubmit a file!




No worries! Just follow the above directions again. We will grade only your last submission.