Add anagram exercise with implementation and tests

ikostan · ikostan · commit 1be5a4f5fcf3 · 2025-11-25T22:12:01.000-08:00
Introduces the anagram exercise including configuration, metadata, help and readme files, the implementation in anagram.py, and comprehensive unit tests in anagram_test.py.
diff --git a/anagram/.exercism/config.json b/anagram/.exercism/config.json
@@ -0,0 +1,38 @@
+{
+  "authors": [],
+  "contributors": [
+    "behrtam",
+    "cmccandless",
+    "crazymykl",
+    "Dog",
+    "dotrungkien",
+    "henrik",
+    "ikhadykin",
+    "kytrinyx",
+    "lowks",
+    "markijbema",
+    "N-Parsons",
+    "n1k0",
+    "pheanex",
+    "roadfoodr",
+    "sjakobi",
+    "thomasjpfan",
+    "tqa236",
+    "vgerak",
+    "yawpitch"
+  ],
+  "files": {
+    "solution": [
+      "anagram.py"
+    ],
+    "test": [
+      "anagram_test.py"
+    ],
+    "example": [
+      ".meta/example.py"
+    ]
+  },
+  "blurb": "Given a word and a list of possible anagrams, select the correct sublist.",
+  "source": "Inspired by the Extreme Startup game",
+  "source_url": "https://github.com/rchatley/extreme_startup"
+}
diff --git a/anagram/.exercism/metadata.json b/anagram/.exercism/metadata.json
@@ -0,0 +1 @@
+{"track":"python","exercise":"anagram","id":"c89b81911fde429d8f7157e018c977e9","url":"https://exercism.org/tracks/python/exercises/anagram","handle":"myFirstCode","is_requester":true,"auto_approve":false}
diff --git a/anagram/HELP.md b/anagram/HELP.md
@@ -0,0 +1,130 @@
+# Help
+
+## Running the tests
+
+We use [pytest][pytest: Getting Started Guide] as our website test runner.
+You will need to install `pytest` on your development machine if you want to run tests for the Python track locally.
+You should also install the following `pytest` plugins:
+
+- [pytest-cache][pytest-cache]
+- [pytest-subtests][pytest-subtests]
+
+Extended information can be found in our website [Python testing guide][Python track tests page].
+
+
+### Running Tests
+
+To run the included tests, navigate to the folder where the exercise is stored using `cd` in your terminal (_replace `{exercise-folder-location}` below with your path_).
+Test files usually end in `_test.py`, and are the same tests that run on the website when a solution is uploaded.
+
+Linux/MacOS
+```bash
+$ cd {path/to/exercise-folder-location}
+```
+
+Windows
+```powershell
+PS C:\Users\foobar> cd {path\to\exercise-folder-location}
+```
+
+<br>
+
+Next, run the `pytest` command in your terminal, replacing `{exercise_test.py}` with the name of the test file:
+
+Linux/MacOS
+```bash
+$ python3 -m pytest -o markers=task {exercise_test.py}
+==================== 7 passed in 0.08s ====================
+```
+
+Windows
+```powershell
+PS C:\Users\foobar> py -m pytest -o markers=task {exercise_test.py}
+==================== 7 passed in 0.08s ====================
+```
+
+
+### Common options
+- `-o` : override default `pytest.ini` (_you can use this to avoid marker warnings_)
+- `-v` : enable verbose output.
+- `-x` : stop running tests on first failure.
+- `--ff` : run failures from previous test before running other test cases.
+
+For additional options, use `python3 -m pytest -h` or `py -m pytest -h`.
+
+
+### Fixing warnings
+
+If you do not use `pytest -o markers=task` when invoking `pytest`, you might receive a `PytestUnknownMarkWarning` for tests that use our new syntax:
+
+```bash
+PytestUnknownMarkWarning: Unknown pytest.mark.task - is this a typo?  You can register custom marks to avoid this warning - for details, see https://docs.pytest.org/en/stable/mark.html
+```
+
+To avoid typing `pytest -o markers=task` for every test you run, you can use a `pytest.ini` configuration file.
+We have made one that can be downloaded from the top level of the Python track directory: [pytest.ini][pytest.ini].
+
+You can also create your own `pytest.ini` file with the following content:
+
+```ini
+[pytest]
+markers =
+    task: A concept exercise task.
+```
+
+Placing the `pytest.ini` file in the _root_ or _working_ directory for your Python track exercises will register the marks and stop the warnings.
+More information on pytest marks can be found in the `pytest` documentation on [marking test functions][pytest: marking test functions with attributes] and the `pytest` documentation on [working with custom markers][pytest: working with custom markers].
+
+Information on customizing pytest configurations can be found in the `pytest` documentation on [configuration file formats][pytest: configuration file formats].
+
+
+### Extending your IDE or Code Editor
+
+Many IDEs and code editors have built-in support for using `pytest` and other code quality tools.
+Some community-sourced options can be found on our [Python track tools page][Python track tools page].
+
+[Pytest: Getting Started Guide]: https://docs.pytest.org/en/latest/getting-started.html
+[Python track tools page]: https://exercism.org/docs/tracks/python/tools
+[Python track tests page]: https://exercism.org/docs/tracks/python/tests
+[pytest-cache]:http://pythonhosted.org/pytest-cache/
+[pytest-subtests]:https://github.com/pytest-dev/pytest-subtests
+[pytest.ini]: https://github.com/exercism/python/blob/main/pytest.ini
+[pytest: configuration file formats]: https://docs.pytest.org/en/6.2.x/customize.html#configuration-file-formats
+[pytest: marking test functions with attributes]: https://docs.pytest.org/en/6.2.x/mark.html#raising-errors-on-unknown-marks
+[pytest: working with custom markers]: https://docs.pytest.org/en/6.2.x/example/markers.html#working-with-custom-markers
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit anagram.py` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Python track's documentation](https://exercism.org/docs/tracks/python)
+- The [Python track's programming category on the forum](https://forum.exercism.org/c/programming/python)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+Below are some resources for getting help if you run into trouble:
+
+- [The PSF](https://www.python.org) hosts Python downloads, documentation, and community resources.
+- [The Exercism Community on Discord](https://exercism.org/r/discord)
+- [Python Community on Discord](https://pythondiscord.com/) is a very helpful and active community.
+- [/r/learnpython/](https://www.reddit.com/r/learnpython/) is a subreddit designed for Python learners.
+- [#python on Libera.chat](https://www.python.org/community/irc/) this is where the core developers for the language hang out and get work done.
+- [Python Community Forums](https://discuss.python.org/)
+- [Free Code Camp Community Forums](https://forum.freecodecamp.org/)
+- [CodeNewbie Community Help Tag](https://community.codenewbie.org/t/help)
+- [Pythontutor](http://pythontutor.com/) for stepping through small code snippets visually.
+
+Additionally, [StackOverflow](http://stackoverflow.com/questions/tagged/python) is a good spot to search for your problem/question to see if it has been answered already.
+ If not - you can always [ask](https://stackoverflow.com/help/how-to-ask) or [answer](https://stackoverflow.com/help/how-to-answer) someone else's question.
diff --git a/anagram/README.md b/anagram/README.md
@@ -0,0 +1,58 @@
+# Anagram
+
+Welcome to Anagram on Exercism's Python Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Introduction
+
+At a garage sale, you find a lovely vintage typewriter at a bargain price!
+Excitedly, you rush home, insert a sheet of paper, and start typing away.
+However, your excitement wanes when you examine the output: all words are garbled!
+For example, it prints "stop" instead of "post" and "least" instead of "stale."
+Carefully, you try again, but now it prints "spot" and "slate."
+After some experimentation, you find there is a random delay before each letter is printed, which messes up the order.
+You now understand why they sold it for so little money!
+
+You realize this quirk allows you to generate anagrams, which are words formed by rearranging the letters of another word.
+Pleased with your finding, you spend the rest of the day generating hundreds of anagrams.
+
+## Instructions
+
+Given a target word and one or more candidate words, your task is to find the candidates that are anagrams of the target.
+
+An anagram is a rearrangement of letters to form a new word: for example `"owns"` is an anagram of `"snow"`.
+A word is _not_ its own anagram: for example, `"stop"` is not an anagram of `"stop"`.
+
+The target word and candidate words are made up of one or more ASCII alphabetic characters (`A`-`Z` and `a`-`z`).
+Lowercase and uppercase characters are equivalent: for example, `"PoTS"` is an anagram of `"sTOp"`, but `"StoP"` is not an anagram of `"sTOp"`.
+The words you need to find should be taken from the candidate words, using the same letter case.
+
+Given the target `"stone"` and the candidate words `"stone"`, `"tones"`, `"banana"`, `"tons"`, `"notes"`, and `"Seton"`, the anagram words you need to find are `"tones"`, `"notes"`, and `"Seton"`.
+
+## Source
+
+### Contributed to by
+
+- @behrtam
+- @cmccandless
+- @crazymykl
+- @Dog
+- @dotrungkien
+- @henrik
+- @ikhadykin
+- @kytrinyx
+- @lowks
+- @markijbema
+- @N-Parsons
+- @n1k0
+- @pheanex
+- @roadfoodr
+- @sjakobi
+- @thomasjpfan
+- @tqa236
+- @vgerak
+- @yawpitch
+
+### Based on
+
+Inspired by the Extreme Startup game - https://github.com/rchatley/extreme_startup
diff --git a/anagram/anagram.py b/anagram/anagram.py
@@ -0,0 +1,30 @@
+"""
+Anagram.
+
+Given a target word and one or more candidate words,
+your task is to find the candidates that are anagrams
+of the target.
+"""
+
+
+def find_anagrams(word: str, candidates: list[str]) -> list[str]:
+    """
+    Return the list of candidates that are anagrams of ``word``.
+
+    Two words are considered anagrams if they consist of the same letters
+    with the same multiplicities when case is ignored. The original casing of
+    candidates is preserved in the returned list. Exact same word (case-insensitive)
+    as the target is excluded.
+
+    :param word: Target word to compare against.
+    :param candidates: Sequence of candidate words to test.
+    :returns: A list containing each candidate that is an anagram of ``word``.
+    """
+    word_ordered_lower_chars: list[str] = sorted(char.lower() for char in word)
+    word_lower = word.lower()
+    return [
+        candidate
+        for candidate in candidates
+        if candidate.lower() != word_lower
+        and sorted(char for char in candidate.lower()) == word_ordered_lower_chars
+    ]
diff --git a/anagram/anagram_test.py b/anagram/anagram_test.py
@@ -0,0 +1,106 @@
+# pylint: disable=C0301, C0114, C0115, C0116, R0904
+# These tests are auto-generated with test data from:
+# https://github.com/exercism/problem-specifications/tree/main/exercises/anagram/canonical-data.json
+# File last updated on 2024-02-28
+
+import unittest
+
+from anagram import (
+    find_anagrams,
+)
+
+
+class AnagramTest(unittest.TestCase):
+    def test_no_matches(self):
+        candidates = ["hello", "world", "zombies", "pants"]
+        expected = []
+        self.assertCountEqual(find_anagrams("diaper", candidates), expected)
+
+    def test_detects_two_anagrams(self):
+        candidates = ["lemons", "cherry", "melons"]
+        expected = ["lemons", "melons"]
+        self.assertCountEqual(find_anagrams("solemn", candidates), expected)
+
+    def test_does_not_detect_anagram_subsets(self):
+        candidates = ["dog", "goody"]
+        expected = []
+        self.assertCountEqual(find_anagrams("good", candidates), expected)
+
+    def test_detects_anagram(self):
+        candidates = ["enlists", "google", "inlets", "banana"]
+        expected = ["inlets"]
+        self.assertCountEqual(find_anagrams("listen", candidates), expected)
+
+    def test_detects_three_anagrams(self):
+        candidates = ["gallery", "ballerina", "regally", "clergy", "largely", "leading"]
+        expected = ["gallery", "regally", "largely"]
+        self.assertCountEqual(find_anagrams("allergy", candidates), expected)
+
+    def test_detects_multiple_anagrams_with_different_case(self):
+        candidates = ["Eons", "ONES"]
+        expected = ["Eons", "ONES"]
+        self.assertCountEqual(find_anagrams("nose", candidates), expected)
+
+    def test_does_not_detect_non_anagrams_with_identical_checksum(self):
+        candidates = ["last"]
+        expected = []
+        self.assertCountEqual(find_anagrams("mass", candidates), expected)
+
+    def test_detects_anagrams_case_insensitively(self):
+        candidates = ["cashregister", "Carthorse", "radishes"]
+        expected = ["Carthorse"]
+        self.assertCountEqual(find_anagrams("Orchestra", candidates), expected)
+
+    def test_detects_anagrams_using_case_insensitive_subject(self):
+        candidates = ["cashregister", "carthorse", "radishes"]
+        expected = ["carthorse"]
+        self.assertCountEqual(find_anagrams("Orchestra", candidates), expected)
+
+    def test_detects_anagrams_using_case_insensitive_possible_matches(self):
+        candidates = ["cashregister", "Carthorse", "radishes"]
+        expected = ["Carthorse"]
+        self.assertCountEqual(find_anagrams("orchestra", candidates), expected)
+
+    def test_does_not_detect_an_anagram_if_the_original_word_is_repeated(self):
+        candidates = ["goGoGO"]
+        expected = []
+        self.assertCountEqual(find_anagrams("go", candidates), expected)
+
+    def test_anagrams_must_use_all_letters_exactly_once(self):
+        candidates = ["patter"]
+        expected = []
+        self.assertCountEqual(find_anagrams("tapper", candidates), expected)
+
+    def test_words_are_not_anagrams_of_themselves(self):
+        candidates = ["BANANA"]
+        expected = []
+        self.assertCountEqual(find_anagrams("BANANA", candidates), expected)
+
+    def test_words_are_not_anagrams_of_themselves_even_if_letter_case_is_partially_different(
+        self,
+    ):
+        candidates = ["Banana"]
+        expected = []
+        self.assertCountEqual(find_anagrams("BANANA", candidates), expected)
+
+    def test_words_are_not_anagrams_of_themselves_even_if_letter_case_is_completely_different(
+        self,
+    ):
+        candidates = ["banana"]
+        expected = []
+        self.assertCountEqual(find_anagrams("BANANA", candidates), expected)
+
+    def test_words_other_than_themselves_can_be_anagrams(self):
+        candidates = ["LISTEN", "Silent"]
+        expected = ["Silent"]
+        self.assertCountEqual(find_anagrams("LISTEN", candidates), expected)
+
+    def test_handles_case_of_greek_letters(self):
+        candidates = ["ΒΓΑ", "ΒΓΔ", "γβα", "αβγ"]
+        expected = ["ΒΓΑ", "γβα"]
+        self.assertCountEqual(find_anagrams("ΑΒΓ", candidates), expected)
+
+    def test_different_characters_may_have_the_same_bytes(self):
+        candidates = ["€a"]
+        expected = []
+        self.assertCountEqual(find_anagrams("a⬂", candidates), expected)

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+{"track":"python","exercise":"anagram","id":"c89b81911fde429d8f7157e018c977e9","url":"https://exercism.org/tracks/python/exercises/anagram","handle":"myFirstCode","is_requester":true,"auto_approve":false}`