From 64012ef885dae148103a0d9e3d74cfc4c2090d67 Mon Sep 17 00:00:00 2001 From: Dmitry Kokorin Date: Tue, 8 Jun 2021 19:41:01 +0300 Subject: [PATCH] Python: grade_school --- .gitignore | 1 + python/grade-school/.exercism/metadata.json | 1 + python/grade-school/README.md | 82 +++++++++++++++++++++ python/grade-school/grade_school.py | 22 ++++++ python/grade-school/grade_school_test.py | 64 ++++++++++++++++ 5 files changed, 170 insertions(+) create mode 100644 python/grade-school/.exercism/metadata.json create mode 100644 python/grade-school/README.md create mode 100644 python/grade-school/grade_school.py create mode 100644 python/grade-school/grade_school_test.py diff --git a/.gitignore b/.gitignore index feb7cdc..e8c6bd8 100644 --- a/.gitignore +++ b/.gitignore @@ -2,3 +2,4 @@ *.swp *.swo **/__pycache__/ +**/.mypy_cache/ diff --git a/python/grade-school/.exercism/metadata.json b/python/grade-school/.exercism/metadata.json new file mode 100644 index 0000000..fb84b19 --- /dev/null +++ b/python/grade-school/.exercism/metadata.json @@ -0,0 +1 @@ +{"track":"python","exercise":"grade-school","id":"0a07ce0d313a4fc7895b13247af40fe6","url":"https://exercism.io/my/solutions/0a07ce0d313a4fc7895b13247af40fe6","handle":"DmitryKokorin","is_requester":true,"auto_approve":false} \ No newline at end of file diff --git a/python/grade-school/README.md b/python/grade-school/README.md new file mode 100644 index 0000000..e339f78 --- /dev/null +++ b/python/grade-school/README.md @@ -0,0 +1,82 @@ +# Grade School + +Given students' names along with the grade that they are in, create a roster +for the school. + +In the end, you should be able to: + +- Add a student's name to the roster for a grade + - "Add Jim to grade 2." + - "OK." +- Get a list of all students enrolled in a grade + - "Which students are in grade 2?" + - "We've only got Jim just now." +- Get a sorted list of all students in all grades. Grades should sort + as 1, 2, 3, etc., and students within a grade should be sorted + alphabetically by name. + - "Who all is enrolled in school right now?" + - "Grade 1: Anna, Barb, and Charlie. Grade 2: Alex, Peter, and Zoe. + Grade 3…" + +Note that all our students only have one name. (It's a small town, what +do you want?) + +## For bonus points + +Did you get the tests passing and the code clean? If you want to, these +are some additional things you could try: + +- If you're working in a language with mutable data structures and your + implementation allows outside code to mutate the school's internal DB + directly, see if you can prevent this. Feel free to introduce additional + tests. + +Then please share your thoughts in a comment on the submission. Did this +experiment make the code better? Worse? Did you learn anything from it? + + +## Exception messages + +Sometimes it is necessary to raise an exception. When you do this, you should include a meaningful error message to +indicate what the source of the error is. This makes your code more readable and helps significantly with debugging. Not +every exercise will require you to raise an exception, but for those that do, the tests will only pass if you include +a message. + +To raise a message with an exception, just write it as an argument to the exception type. For example, instead of +`raise Exception`, you should write: + +```python +raise Exception("Meaningful message indicating the source of the error") +``` + +## Running the tests + +To run the tests, run `pytest grade_school_test.py` + +Alternatively, you can tell Python to run the pytest module: +`python -m pytest grade_school_test.py` + +### Common `pytest` options + +- `-v` : enable verbose output +- `-x` : stop running tests on first failure +- `--ff` : run failures from previous test before running other test cases + +For other options, see `python -m pytest -h` + +## Submitting Exercises + +Note that, when trying to submit an exercise, make sure the solution is in the `$EXERCISM_WORKSPACE/python/grade-school` directory. + +You can find your Exercism workspace by running `exercism debug` and looking for the line that starts with `Workspace`. + +For more detailed information about running tests, code style and linting, +please see [Running the Tests](http://exercism.io/tracks/python/tests). + +## Source + +A pairing session with Phil Battos at gSchool [http://gschool.it](http://gschool.it) + +## Submitting Incomplete Solutions + +It's possible to submit an incomplete solution so you can see how others have completed the exercise. diff --git a/python/grade-school/grade_school.py b/python/grade-school/grade_school.py new file mode 100644 index 0000000..96b8b6a --- /dev/null +++ b/python/grade-school/grade_school.py @@ -0,0 +1,22 @@ +import bisect +from collections import defaultdict +from typing import List, DefaultDict + + +class School: + def __init__(self) -> None: + self.student_db: DefaultDict[int, List[str]] = defaultdict(list) + + def add_student(self, name: str, grade: int) -> None: + bisect.insort(self.student_db[grade], name) + + def grade(self, grade_number: int) -> List[str]: + + if grade_number not in self.student_db.keys(): + return [] + + return self.student_db[grade_number] + + def roster(self) -> List[str]: + return sum([self.grade(grade_number) for grade_number + in sorted(self.student_db)], []) diff --git a/python/grade-school/grade_school_test.py b/python/grade-school/grade_school_test.py new file mode 100644 index 0000000..02642a5 --- /dev/null +++ b/python/grade-school/grade_school_test.py @@ -0,0 +1,64 @@ +import unittest + +from grade_school import School + +# Tests adapted from `problem-specifications//canonical-data.json` + + +class GradeSchoolTest(unittest.TestCase): + def test_adding_a_student_adds_them_to_the_sorted_roster(self): + school = School() + school.add_student(name="Aimee", grade=2) + expected = ["Aimee"] + self.assertEqual(school.roster(), expected) + + def test_adding_more_student_adds_them_to_the_sorted_roster(self): + school = School() + school.add_student(name="Blair", grade=2) + school.add_student(name="James", grade=2) + school.add_student(name="Paul", grade=2) + expected = ["Blair", "James", "Paul"] + self.assertEqual(school.roster(), expected) + + def test_adding_students_to_different_grades_adds_them_to_the_same_sorted_roster( + self + ): + school = School() + school.add_student(name="Chelsea", grade=3) + school.add_student(name="Logan", grade=7) + expected = ["Chelsea", "Logan"] + self.assertEqual(school.roster(), expected) + + def test_roster_returns_an_empty_list_if_there_are_no_students_enrolled(self): + school = School() + expected = [] + self.assertEqual(school.roster(), expected) + + def test_student_names_with_grades_are_displayed_in_the_same_sorted_roster(self): + school = School() + school.add_student(name="Peter", grade=2) + school.add_student(name="Anna", grade=1) + school.add_student(name="Barb", grade=1) + school.add_student(name="Zoe", grade=2) + school.add_student(name="Alex", grade=2) + school.add_student(name="Jim", grade=3) + school.add_student(name="Charlie", grade=1) + expected = ["Anna", "Barb", "Charlie", "Alex", "Peter", "Zoe", "Jim"] + self.assertEqual(school.roster(), expected) + + def test_grade_returns_the_students_in_that_grade_in_alphabetical_order(self): + school = School() + school.add_student(name="Franklin", grade=5) + school.add_student(name="Bradley", grade=5) + school.add_student(name="Jeff", grade=1) + expected = ["Bradley", "Franklin"] + self.assertEqual(school.grade(5), expected) + + def test_grade_returns_an_empty_list_if_there_are_no_students_in_that_grade(self): + school = School() + expected = [] + self.assertEqual(school.grade(1), expected) + + +if __name__ == "__main__": + unittest.main()