diff --git a/atbash-cipher/.exercism/config.json b/atbash-cipher/.exercism/config.json new file mode 100644 index 0000000..5df5062 --- /dev/null +++ b/atbash-cipher/.exercism/config.json @@ -0,0 +1,33 @@ +{ + "authors": [ + "betegelse" + ], + "contributors": [ + "behrtam", + "cmccandless", + "Dog", + "ikhadykin", + "jgomo3", + "kytrinyx", + "N-Parsons", + "parinporecha", + "pheanex", + "sjakobi", + "thomasjpfan", + "tqa236" + ], + "files": { + "solution": [ + "atbash_cipher.py" + ], + "test": [ + "atbash_cipher_test.py" + ], + "example": [ + ".meta/example.py" + ] + }, + "blurb": "Create an implementation of the Atbash cipher, an ancient encryption system created in the Middle East.", + "source": "Wikipedia", + "source_url": "https://en.wikipedia.org/wiki/Atbash" +} diff --git a/atbash-cipher/.exercism/metadata.json b/atbash-cipher/.exercism/metadata.json new file mode 100644 index 0000000..16c983f --- /dev/null +++ b/atbash-cipher/.exercism/metadata.json @@ -0,0 +1 @@ +{"track":"python","exercise":"atbash-cipher","id":"888b453465e64f5d91aea849caf4077c","url":"https://exercism.org/tracks/python/exercises/atbash-cipher","handle":"myFirstCode","is_requester":true,"auto_approve":false} \ No newline at end of file diff --git a/atbash-cipher/HELP.md b/atbash-cipher/HELP.md new file mode 100644 index 0000000..90e344d --- /dev/null +++ b/atbash-cipher/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} +``` + +
+ +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 atbash_cipher.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. \ No newline at end of file diff --git a/atbash-cipher/README.md b/atbash-cipher/README.md new file mode 100644 index 0000000..cc5d254 --- /dev/null +++ b/atbash-cipher/README.md @@ -0,0 +1,57 @@ +# Atbash Cipher + +Welcome to Atbash Cipher on Exercism's Python Track. +If you need help running the tests or submitting your code, check out `HELP.md`. + +## Instructions + +Create an implementation of the Atbash cipher, an ancient encryption system created in the Middle East. + +The Atbash cipher is a simple substitution cipher that relies on transposing all the letters in the alphabet such that the resulting alphabet is backwards. +The first letter is replaced with the last letter, the second with the second-last, and so on. + +An Atbash cipher for the Latin alphabet would be as follows: + +```text +Plain: abcdefghijklmnopqrstuvwxyz +Cipher: zyxwvutsrqponmlkjihgfedcba +``` + +It is a very weak cipher because it only has one possible key, and it is a simple mono-alphabetic substitution cipher. +However, this may not have been an issue in the cipher's time. + +Ciphertext is written out in groups of fixed length, the traditional group size being 5 letters, leaving numbers unchanged, and punctuation is excluded. +This is to make it harder to guess things based on word boundaries. +All text will be encoded as lowercase letters. + +## Examples + +- Encoding `test` gives `gvhg` +- Encoding `x123 yes` gives `c123b vh` +- Decoding `gvhg` gives `test` +- Decoding `gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt` gives `thequickbrownfoxjumpsoverthelazydog` + +## Source + +### Created by + +- @betegelse + +### Contributed to by + +- @behrtam +- @cmccandless +- @Dog +- @ikhadykin +- @jgomo3 +- @kytrinyx +- @N-Parsons +- @parinporecha +- @pheanex +- @sjakobi +- @thomasjpfan +- @tqa236 + +### Based on + +Wikipedia - https://en.wikipedia.org/wiki/Atbash \ No newline at end of file diff --git a/atbash-cipher/atbash_cipher.py b/atbash-cipher/atbash_cipher.py new file mode 100644 index 0000000..f6e5436 --- /dev/null +++ b/atbash-cipher/atbash_cipher.py @@ -0,0 +1,69 @@ +""" +This is an implementation of the 'Atbash' cipher, an ancient +encryption system created in the Middle East. +""" + +import string + +alphabet: str = string.ascii_lowercase + + +def encode(plain_text: str) -> str: + """ + Encode text using the Atbash cipher. + + Letters are mirrored in the lowercase Latin alphabet; digits are preserved. + Punctuation characters '.,!?' and spaces are removed. The result is grouped + into 5-character blocks separated by spaces for readability. + + :param plain_text: Input text to encode. + :type plain_text: str + :returns: Encoded text (grouped in 5-character blocks when length >= 5). + :rtype: str + """ + temp_txt: [str] = [ + _replace(char) for char in plain_text if char not in ".,!? " + ] + if len(temp_txt) > 4: + step: int = 5 + i_start: int = 0 + i_end: int = i_start + step + txt: list[str] = [] + while i_start <= len(temp_txt): + tmp: str = "".join(temp_txt[i_start:i_end]) + if tmp: + txt.append(tmp) + i_start, i_end = i_end, i_end + step + return " ".join(txt) + return "".join(temp_txt) + + +def _replace(char: str) -> str: + """ + Apply Atbash mapping to a single character. + + Alphabetic characters are lowercased and mirrored in the alphabet; + non-letters are returned unchanged. + + :param char: Character to transform. + :type char: str + :returns: Transformed character. + :rtype: str + """ + if char.lower().isalpha(): + return alphabet[-(alphabet.index(char.lower()) + 1)] + return char + + +def decode(ciphered_text: str) -> str: + """ + Decode an Atbash-encoded string. + + Atbash is symmetric; decoding reuses encoding and removes grouping spaces. + + :param ciphered_text: Encoded text, optionally grouped with spaces. + :type ciphered_text: str + :returns: Decoded text without grouping spaces. + :rtype: str + """ + return encode(ciphered_text).replace(" ", "") diff --git a/atbash-cipher/atbash_cipher_test.py b/atbash-cipher/atbash_cipher_test.py new file mode 100644 index 0000000..b5d8dcc --- /dev/null +++ b/atbash-cipher/atbash_cipher_test.py @@ -0,0 +1,66 @@ +# 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/atbash-cipher/canonical-data.json +# File last updated on 2023-07-20 + +import unittest + +from atbash_cipher import ( + decode, + encode, +) + + +class AtbashCipherTest(unittest.TestCase): + def test_encode_yes(self): + self.assertEqual(encode("yes"), "bvh") + + def test_encode_no(self): + self.assertEqual(encode("no"), "ml") + + def test_encode_omg(self): + self.assertEqual(encode("OMG"), "lnt") + + def test_encode_spaces(self): + self.assertEqual(encode("O M G"), "lnt") + + def test_encode_mindblowingly(self): + self.assertEqual(encode("mindblowingly"), "nrmwy oldrm tob") + + def test_encode_numbers(self): + self.assertEqual(encode("Testing,1 2 3, testing."), "gvhgr mt123 gvhgr mt") + + def test_encode_deep_thought(self): + self.assertEqual(encode("Truth is fiction."), "gifgs rhurx grlm") + + def test_encode_all_the_letters(self): + self.assertEqual( + encode("The quick brown fox jumps over the lazy dog."), + "gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt", + ) + + def test_decode_exercism(self): + self.assertEqual(decode("vcvix rhn"), "exercism") + + def test_decode_a_sentence(self): + self.assertEqual( + decode("zmlyh gzxov rhlug vmzhg vkkrm thglm v"), + "anobstacleisoftenasteppingstone", + ) + + def test_decode_numbers(self): + self.assertEqual(decode("gvhgr mt123 gvhgr mt"), "testing123testing") + + def test_decode_all_the_letters(self): + self.assertEqual( + decode("gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt"), + "thequickbrownfoxjumpsoverthelazydog", + ) + + def test_decode_with_too_many_spaces(self): + self.assertEqual(decode("vc vix r hn"), "exercism") + + def test_decode_with_no_spaces(self): + self.assertEqual( + decode("zmlyhgzxovrhlugvmzhgvkkrmthglmv"), "anobstacleisoftenasteppingstone" + )