jjzcru/student-repository

Homework 09

You've been hired by Stevens Institute of Technology to create a data repository of courses, students, and instructors. The system will be used to help students track their required courses, the courses they have successfully completed, their grades, GPA, etc. The system will also be used by faculty advisors to help students to create study plans. We will continue to add new features to this solution over the coming weeks so you'll want to think carefully about a good design and implementation.

Your assignment this week is to begin to build the framework for your project and summarize student and instructor data. You'll need to download three ASCII, tab separated, data files:

1. students.txt

   • Provides information about each student.
   • Each line has the format: CWID\tName\tMajor (where \t is the character)

2. instructors.txt

   • Provides information about each instructor.
   • Each line has the format: CWID\tName\tDepartment (where \t is the character)

3. grades.txt:

   • Specifies the student CWID, course, and grade for that course, and the instructor CWID.
   • Each line has the format: Student CWID\tCourse\tLetterGrade\tInstructor CWID

Your assignment is to read the data from each of the three files and store it in a collection of classes that are easy to process to meet the following requirements:

• Your solution should allow a single program to create repositories for different sets of data files, e.g. one set of files for Stevens, another for Columbia University, and a third for NYU. Each university will have different directories of data files. Hint: you should define a class to hold all of the information for a specific university.
• You may hard code the names of each of the required data file names within a directory, e.g. "students.txt", "instructors.txt", and "grades.txt". Your solution should accept the directory path where the three data files exist so you can easily create multiple sets of input files for testing. I'll test your solution against multiple data directories representing different universities so be sure your solution allows me to easily run against multiple data directories.
• Use your file reader from HW08 to read the students, instructors, and grades files into appropriate data structures or classes.
• Print warning messages if the input file doesn't exist or doesn't meet the expected format.
• Print warning messages if the grades file includes an unknown instructor or student
• Use PrettyTable to generate and print a summary table of all of the students with their CWID, name, and a sorted list of the courses they've taken (as specified in the grades.txt file).
• Use PrettyTable to generate and print a summary table of each of the instructors who taught at least one course with their CWID, name, department, the course they've taught, and the number of students in each class.
• Implement automated tests to verify that the data in the prettytables matches the data from the input data files.
• You do NOT need to implement automated tests to catch all possible error conditions but your program should print relevant error messages when invalid or missing data is detected.
• Your solution SHOULD print error messages and warnings to the user about inconsistent or bad data, e.g. a data file with the wrong number of fields or a grade for an unknown student or instructor.

Design choice

• The code is split into multiple files for Student, Instructor and Grade. Each module is independent of each other, by looking at the import statements you will see that they only use python primitives.
• Each module has a static method called from_file, and the job its to provide an accessible way to load information while respecting the encapsulation of the module. Is more of a utility function.
• The University class have instructor, grade and student as dependencies, personally I prefer composition to inheritance, that's the reason that I didn't want to create a dependency between grades and student, and grades with professor.
• For the student.py you will see three classes:
  • Student Is just a data object, it doesn't have any methods
  • GetBy: This is just to define an enum I created, so I can take advantage of the autocomplete and feels more self documenting than using str.
  • Students: It uses the repository pattern, the goal of this class is to provide functions that make it easy to manipulate the data on the list. I created a function call get that uses the GetBy enum to provide different way to request data while being flexible enough to be extended in the future. (Open/Close Principle). The list is private, so it uses methods to request the data.
• For the instructor.py you will see three classes:
  • Instructor Is just a data object, it doesn't have any methods
  • GetBy: This is just to define an enum I created, so i can take advantage of the autocomplete and feels more self documenting than using str.
  • Instructors: It uses the repository pattern, the goal of this class is to provide functions that make it easy to manipulate the data on the list. I created a function call get that uses the GetBy enum to provide different way to request data while being flexible enough to be extended in the future. (Open/Close Principle) The list is private, so it uses methods to request the data.
• For the grade.py you will see three classes:
  • Grade Is just a data object, it doesn't have any methods
  • GetBy: This is just to define an enum I created, so I can take advantage of the autocomplete and feels more self documenting than using str.
  • Grades: It uses the repository pattern, the goal of this class is to provide functions that make it easy to manipulate the data on the list. I created a function call get that uses the GetBy enum to provide different way to request data while being flexible enough to be extended in the future. (Open/Close Principle). The list is private, so it uses methods to request the data.