Python - Storing Data Using Other Collection Types - データベース、辞書の辞書、辞書のネスト、keysメソッド、valuesメソッド、Set、和集合

Practical Programming
楽天ブックス 紀伊国屋書店

開発環境

• macOS Catalina - Apple (OS)
• Emacs (Text Editor)
• Windows 10 Pro (OS)
• Visual Studio Code (Text Editor)
• Python 3.8 (プログラミング言語)

Practical Programming: An Introduction to Computer Science Using Python 3.6 (Paul Gries(著)、Jennifer Campbell(著)、Jason Montojo(著)、Pragmatic Bookshelf)のChapter 11(Storing Data Using Other Collection Types)、Exercise 10、11の解答を求めてみる。

コード

#!/usr/bin/env python3
from unittest import TestCase, main
from typing import Any, Dict, Set

print('10, 11.')


class TestDBHeadings(TestCase):
    def test_empty(self):
        self.assertEqual(db_headings({}), set())

    def test_empty1(self):
        self.assertEqual(db_headings({'a': {}}), set())

    def test_other(self):
        self.assertEqual(db_headings({'a': {'b': 1},
                                      'c': {'d': 2, 'e': 3},
                                      'f': {'d': 4}}),
                         {'b', 'd', 'e'})


class TestDBConsistent(TestCase):
    def test_empty(self):
        self.assertEqual(db_consistent({}), True)

    def test_empty1(self):
        self.assertEqual(db_consistent({'a': {}}), True)

    def test_false(self):
        self.assertEqual(db_consistent({'a': {'b': 1},
                                        'c': {'d': 2, 'e': 3},
                                        'f': {'d': 4}}),
                         False)

    def test_true(self):
        self.assertEqual(db_consistent({'a': {'b': 1,
                                              'c': 2},
                                        'd': {'b': 3,
                                              'c': 4},
                                        'e': {'b': 5,
                                              'c': 6}}),
                         True)


def db_headings(db: Dict[str, Dict[str, Any]]) -> Set[str]:
    headings = set()
    for value in db.values():
        if value:
            headings |= set(value.keys())
    return headings


def db_consistent(db: Dict[str, Dict[str, Any]]) -> bool:
    values = list(db.values())
    if not values:
        return True
    headings = set(values[0])
    for value in values[1:]:
        if headings != set(value):
            return False
    return True


if __name__ == "__main__":
    main()

入出力結果(Zsh、PowerShell、Terminal、Jupyter(IPython))

% ./sample10.py -v
10, 11.
test_empty (__main__.TestDBConsistent) ... ok
test_empty1 (__main__.TestDBConsistent) ... ok
test_false (__main__.TestDBConsistent) ... ok
test_true (__main__.TestDBConsistent) ... ok
test_empty (__main__.TestDBHeadings) ... ok
test_empty1 (__main__.TestDBHeadings) ... ok
test_other (__main__.TestDBHeadings) ... ok

----------------------------------------------------------------------
Ran 7 tests in 0.000s

OK
%