Grades Module

Introduction

In this exercise you will practice

• writing functions,
• using control structures, and
• manipulating data structures.

Problem Description

You need to process grades given as a list of lists, list[list[str]], where the first list is a header, and subsequent lists have a name followed by grades. For example:

super_grades = [
    # First line is descriptive header. Subsequent lines hold data
    ['Student', 'Exam 1', 'Exam 2', 'Exam 3'],
    ['Thorny', '100', '90', '80'],
    ['Mac', '88', '99', '111'],
    ['Farva', '45', '56', '67'],
    ['Rabbit', '59', '61', '67'],
    ['Ursula', '73', '79', '83'],
    ['Foster', '89', '97', '101']
]

Write a module named grades with the following functions:

• aslists(grades), which takes a grades list as specified above and creates a dict[str, list[float]] mapping names to lists of grades.

• asdicts(grades), which takes a grades list as specified above and creates a dict[str, dict[str, float]] mapping names to dictionaries of grades.

• stud_means(grades), which takes a dict[str, list[float]] mapping names to lists of grades and creates a dict mapping names to grade means.

• item_mean(grades, item), which takes a dict[str, dict[str, float]] and create a dict[str, float] mapping items to average for that item across all students.

• (Optional) rank(grades, item), which takes a dict[str, dict[str, float]] mapping names to dicts of grades and returns a list[tuple[str, float]] of (student, grade) pairs where grade is the grade for student on item, sorted in descending order by the grades.

  • You may find the sorted function helpful. You’ll also need to understand higher-order functions

Sample Solution

Don’t peek until you’ve tried it yourself first!

• grades.py