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ekingery's solution

to Kindergarten Garden in the Python Track

Published at Nov 21 2019 · 0 comments
Instructions
Test suite
Solution

Note:

This exercise has changed since this solution was written.

Given a diagram, determine which plants each child in the kindergarten class is responsible for.

The kindergarten class is learning about growing plants. The teacher thought it would be a good idea to give them actual seeds, plant them in actual dirt, and grow actual plants.

They've chosen to grow grass, clover, radishes, and violets.

To this end, the children have put little cups along the window sills, and planted one type of plant in each cup, choosing randomly from the available types of seeds.

[window][window][window]
........................ # each dot represents a cup
........................

There are 12 children in the class:

  • Alice, Bob, Charlie, David,
  • Eve, Fred, Ginny, Harriet,
  • Ileana, Joseph, Kincaid, and Larry.

Each child gets 4 cups, two on each row. Their teacher assigns cups to the children alphabetically by their names.

The following diagram represents Alice's plants:

[window][window][window]
VR......................
RG......................

In the first row, nearest the windows, she has a violet and a radish. In the second row she has a radish and some grass.

Your program will be given the plants from left-to-right starting with the row nearest the windows. From this, it should be able to determine which plants belong to each student.

For example, if it's told that the garden looks like so:

[window][window][window]
VRCGVVRVCGGCCGVRGCVCGCGV
VRCCCGCRRGVCGCRVVCVGCGCV

Then if asked for Alice's plants, it should provide:

  • Violets, radishes, violets, radishes

While asking for Bob's plants would yield:

  • Clover, grass, clover, clover

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:

raise Exception("Meaningful message indicating the source of the error")

Running the tests

To run the tests, run pytest kindergarten_garden_test.py

Alternatively, you can tell Python to run the pytest module: python -m pytest kindergarten_garden_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/kindergarten-garden 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.

Source

Random musings during airplane trip. http://jumpstartlab.com

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

kindergarten_garden_test.py

import unittest

from kindergarten_garden import Garden

# Tests adapted from `problem-specifications//canonical-data.json` @ v1.1.1


class KindergartenGardenTest(unittest.TestCase):
    def test_partial_garden_garden_with_single_student(self):
        garden = Garden("RC\nGG")
        self.assertEqual(
            garden.plants("Alice"), ["Radishes", "Clover", "Grass", "Grass"]
        )

    def test_partial_garden_different_garden_with_single_student(self):
        garden = Garden("VC\nRC")
        self.assertEqual(
            garden.plants("Alice"), ["Violets", "Clover", "Radishes", "Clover"]
        )

    def test_partial_garden_garden_with_two_students(self):
        garden = Garden("VVCG\nVVRC")
        self.assertEqual(
            garden.plants("Bob"), ["Clover", "Grass", "Radishes", "Clover"]
        )

    def test_partial_garden_second_student_s_garden(self):
        garden = Garden("VVCCGG\nVVCCGG")
        self.assertEqual(garden.plants("Bob"), ["Clover", "Clover", "Clover", "Clover"])

    def test_partial_garden_third_student_s_garden(self):
        garden = Garden("VVCCGG\nVVCCGG")
        self.assertEqual(garden.plants("Charlie"), ["Grass", "Grass", "Grass", "Grass"])

    def test_full_garden_first_student_s_garden(self):
        garden = Garden("VRCGVVRVCGGCCGVRGCVCGCGV\nVRCCCGCRRGVCGCRVVCVGCGCV")
        self.assertEqual(
            garden.plants("Alice"), ["Violets", "Radishes", "Violets", "Radishes"]
        )

    def test_full_garden_second_student_s_garden(self):
        garden = Garden("VRCGVVRVCGGCCGVRGCVCGCGV\nVRCCCGCRRGVCGCRVVCVGCGCV")
        self.assertEqual(garden.plants("Bob"), ["Clover", "Grass", "Clover", "Clover"])

    def test_full_garden_second_to_last_student_s_garden(self):
        garden = Garden("VRCGVVRVCGGCCGVRGCVCGCGV\nVRCCCGCRRGVCGCRVVCVGCGCV")
        self.assertEqual(
            garden.plants("Kincaid"), ["Grass", "Clover", "Clover", "Grass"]
        )

    def test_full_garden_last_student_s_garden(self):
        garden = Garden("VRCGVVRVCGGCCGVRGCVCGCGV\nVRCCCGCRRGVCGCRVVCVGCGCV")
        self.assertEqual(
            garden.plants("Larry"), ["Grass", "Violets", "Clover", "Violets"]
        )

    # Additional tests for this track

    def test_students_are_unordered_first_student(self):
        garden = Garden(
            "VCRRGVRG\nRVGCCGCV", students=["Samantha", "Patricia", "Xander", "Roger"]
        )
        self.assertEqual(
            garden.plants("Patricia"), ["Violets", "Clover", "Radishes", "Violets"]
        )

    def test_students_are_unordered_last_student(self):
        garden = Garden(
            "VCRRGVRG\nRVGCCGCV", students=["Samantha", "Patricia", "Xander", "Roger"]
        )
        self.assertEqual(
            garden.plants("Xander"), ["Radishes", "Grass", "Clover", "Violets"]
        )


if __name__ == "__main__":
    unittest.main()
class Garden:
    STUDENTS = ["Alice", "Bob", "Charlie", "David", "Eve", "Fred", "Ginny",
                "Harriet", "Ileana", "Joseph", "Kincaid", "Larry"]
    PLANTS = {"C": "Clover", "G": "Grass", "R": "Radishes", "V": "Violets"}
    NUM_CUPS_PER_STUDENT = 2

    def __init__(self, diagram, students=None):
        # The teacher assigns cups to children alphabetically by their names
        students = sorted(students or self.STUDENTS)

        # this is valid as long as NUM_ROWS = 2
        row1, row2 = diagram.splitlines()

        # the names of each plant, indexed by student name
        self.cups = {}

        # loop for all students (row lengths are assumed to be equal)
        for index, student in enumerate(students[:len(row1)]):
            # a is the index starting position of the student
            a = index * self.NUM_CUPS_PER_STUDENT
            # b value is the index ending position of the student
            b = a + self.NUM_CUPS_PER_STUDENT

            # handle invalid input by assigning an empty list
            self.cups.setdefault(student, [])

            # assign the plant in each row corresponding to the current student
            self.cups[student].extend(
                self.PLANTS[plant] for plant in row1[a:b]
            )
            self.cups[student].extend(
                self.PLANTS[plant] for plant in row2[a:b]
            )

    def plants(self, student):
        return self.cups.get(student, [])

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