Summary  
Demonstrates how to use a dictionary’s popitem() method to remove and return its last inserted key-value pair.

General domain of usage  
Data processing

Sanakirjoilla on myös `popitem()`-metodi, joka poistaa ja palauttaa viimeisen avain-arvo-parin.

book = {
    "title": "Pride and Prejudice",
    "author": "Jane Austen",
    "year": 1813,
    "genre": "Romance"
}

# Removing the last key-value pair using popitem()
popped_item = book.popitem()

# Printing the updated dictionary and the removed pair
print("Removed item:", popped_item)
print("Updated dictionary:", book)

import unittest
import importlib

def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)

class TestUserCode(unittest.TestCase):

    def test_authors_books_is_declared(self):
        import user_code
        _dynamic_test(
            self,
            hasattr(user_code, 'authors_books'),
            "The `authors_books` dictionary is declared.",
            "Expected `authors_books` to be declared."
        )

    def test_authors_books_is_dict(self):
        import user_code
        _dynamic_test(
            self,
            isinstance(user_code.authors_books, dict),
            "The `authors_books` is of type `dict`.",
            "Expected `authors_books` to be of type `dict`."
        )

    def test_removed_element_is_declared(self):
        import user_code
        _dynamic_test(
            self,
            hasattr(user_code, 'removed_element'),
            "The `removed_element` variable is declared.",
            "Expected `removed_element` to be declared."
        )

    def test_removed_element_was_last(self):
        import user_code
        expected_last_key = 'Agatha Christie'
        _dynamic_test(
            self,
            isinstance(user_code.removed_element, tuple) and user_code.removed_element[0] == expected_last_key,
            "The last element was correctly removed using `popitem()`.",
            "Expected only the last element to be removed using `popitem()`"
        )

    def test_mark_twain_is_added(self):
        import user_code
        expected_books = [
            'The Adventures of Tom Sawyer',
            'Adventures of Huckleberry Finn',
            'The Prince and the Pauper'
        ]
        _dynamic_test(
            self,
            'Mark Twain' in user_code.authors_books and user_code.authors_books['Mark Twain'] == expected_books,
            "The `Mark Twain` entry was added correctly.",
            "Expected `Mark Twain` to be in `authors_books` with the correct book list."
        )

    def test_other_authors_exist(self):
        import user_code
        expected_authors = {
            'William Shakespeare', 'J.K. Rowling', 'George Orwell', 'Stephen King'
        }
        _dynamic_test(
            self,
            expected_authors.issubset(set(user_code.authors_books.keys())),
            "Other authors are still present in `authors_books`.",
            "Some expected authors are missing from `authors_books`."
        )

    def test_popitem_method_used(self):
        with open('user_code.py', 'r') as file:
            user_code_source = file.read()
        _dynamic_test(
            self,
            "popitem()" in user_code_source,
            "The `popitem()` method is used to remove the last element.",
            "Expected the `popitem()` method to be used to remove the last element."
        )

if __name__ == '__main__':
    unittest.main()

test_main.py

Tutustu Python-ohjelmointikielen keskeisiin tietorakenteisiin, kuten listoihin, sanakirjoihin, tuplihin ja joukkoihin, sekä opi hyödyntämään niitä tehokkaasti todellisten ohjelmointiongelmien ratkaisemisessa.

Mikä on lista? Lista on järjestetty kokoelma, jota voidaan muokata. Se sallii myös päällekkäiset alkiot.

Viimeksi Lisätyn Alkion Poistaminen Pythonissa

Ratkaisu