Python diff of squares

python/README.md

@@ -43,3 +43,4 @@
 - [reverse-string](./reverse-string/README.md)
 - [roman-numerals](./roman-numerals/README.md)
 - [scrabble-score](./scrabble-score/README.md)
+- [difference-of-squares](./difference-of-squares/README.md)

python/difference-of-squares/.coverage

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+!coverage.py: This is a private format, don't read it directly!{"arcs":{"/home/vpayno/git_vpayno/exercism-workspace/python/difference-of-squares/test/__init__.py":[[0,0],[0,-1]],"/home/vpayno/git_vpayno/exercism-workspace/python/difference-of-squares/difference_of_squares.py":[[0,1],[1,4],[4,14],[14,24],[24,-1],[24,31],[4,11],[11,-4],[14,21],[21,-14],[31,-24]]}}

python/difference-of-squares/.coverage.xml

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+<?xml version="1.0" ?>
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+	<!-- Generated by coverage.py: https://coverage.readthedocs.io -->
+	<!-- Based on https://raw.githubusercontent.com/cobertura/web/master/htdocs/xml/coverage-04.dtd -->
+	<sources>
+		<source>/home/vpayno/git_vpayno/exercism-workspace/python/difference-of-squares</source>
+	</sources>
+	<packages>
+		<package branch-rate="1" complexity="0" line-rate="0.8571" name=".">
+			<classes>
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+		<package branch-rate="1" complexity="0" line-rate="1" name="test">
+			<classes>
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+		</package>
+	</packages>
+</coverage>

python/difference-of-squares/.coveragerc

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+[run]
+omit = __init__.py, *_test.py

python/difference-of-squares/.exercism/config.json

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+{
+  "authors": [
+    "sjakobi"
+  ],
+  "contributors": [
+    "akashsara",
+    "behrtam",
+    "BethanyG",
+    "cmccandless",
+    "Dog",
+    "ikhadykin",
+    "kytrinyx",
+    "N-Parsons",
+    "pheanex",
+    "tqa236",
+    "yawpitch"
+  ],
+  "files": {
+    "solution": [
+      "difference_of_squares.py"
+    ],
+    "test": [
+      "difference_of_squares_test.py"
+    ],
+    "example": [
+      ".meta/example.py"
+    ]
+  },
+  "blurb": "Find the difference between the square of the sum and the sum of the squares of the first N natural numbers.",
+  "source": "Problem 6 at Project Euler",
+  "source_url": "https://projecteuler.net/problem=6"
+}

python/difference-of-squares/.exercism/metadata.json

@@ -0,0 +1 @@
+{"track":"python","exercise":"difference-of-squares","id":"8cc46c1c99e54251a9d2d72628b6ae3e","url":"https://exercism.org/tracks/python/exercises/difference-of-squares","handle":"vpayno","is_requester":true,"auto_approve":false}

python/difference-of-squares/.pylintrc

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+../.pylintrc

python/difference-of-squares/HELP.md

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+# 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 difference_of_squares.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.

python/difference-of-squares/README.md

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+# Difference of Squares
+
+Welcome to Difference of Squares on Exercism's Python Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Instructions
+
+Find the difference between the square of the sum and the sum of the squares of the first N natural numbers.
+
+The square of the sum of the first ten natural numbers is
+(1 + 2 + ... + 10)² = 55² = 3025.
+
+The sum of the squares of the first ten natural numbers is
+1² + 2² + ... + 10² = 385.
+
+Hence the difference between the square of the sum of the first ten natural numbers and the sum of the squares of the first ten natural numbers is 3025 - 385 = 2640.
+
+You are not expected to discover an efficient solution to this yourself from first principles; research is allowed, indeed, encouraged.
+Finding the best algorithm for the problem is a key skill in software engineering.
+
+## Source
+
+### Created by
+
+- @sjakobi
+
+### Contributed to by
+
+- @akashsara
+- @behrtam
+- @BethanyG
+- @cmccandless
+- @Dog
+- @ikhadykin
+- @kytrinyx
+- @N-Parsons
+- @pheanex
+- @tqa236
+- @yawpitch
+
+### Based on
+
+Problem 6 at Project Euler - https://projecteuler.net/problem=6
+
+### My Solution
+
+- [my solution](./difference_of_squares.py)
+- [run-tests](./run-tests-python.txt)

python/difference-of-squares/difference_of_squares.py

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+"""Python Difference of Squares Exercism"""
+
+
+def square_of_sum(number: int) -> int:
+    """Calculates the square of sum.
+
+    :param number: int
+    :return: int
+    """
+
+    return (number * (number + 1) // 2) ** 2
+
+
+def sum_of_squares(number: int) -> int:
+    """Calculates the sum of squares.
+
+    :param number: int
+    :return: int
+    """
+
+    return (number * (number + 1) * (2 * number + 1)) // 6
+
+
+def difference_of_squares(number: int) -> int:
+    """Calculates the difference of squares.
+
+    :param number: int
+    :return: int
+    """
+
+    return square_of_sum(number) - sum_of_squares(number)

python/difference-of-squares/difference_of_squares.py,cover

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+> """Python Difference of Squares Exercism"""
+
+
+> def square_of_sum(number: int) -> int:
+>     """Calculates the square of sum.
+
+>     :param number: int
+>     :return: int
+>     """
+
+>     return (number * (number + 1) // 2) ** 2
+
+
+> def sum_of_squares(number: int) -> int:
+>     """Calculates the sum of squares.
+
+>     :param number: int
+>     :return: int
+>     """
+
+>     return (number * (number + 1) * (2 * number + 1)) // 6
+
+
+> def difference_of_squares(number: int) -> int:
+>     """Calculates the difference of squares.
+
+>     :param number: int
+>     :return: int
+>     """
+
+>     return square_of_sum(number) - sum_of_squares(number)

python/difference-of-squares/difference_of_squares_test.py

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+# These tests are auto-generated with test data from:
+# https://github.com/exercism/problem-specifications/tree/main/exercises/difference-of-squares/canonical-data.json
+# File last updated on 2023-07-19
+
+import unittest
+
+from difference_of_squares import (
+    difference_of_squares,
+    square_of_sum,
+    sum_of_squares,
+)
+
+
+class DifferenceOfSquaresTest(unittest.TestCase):
+    def test_square_of_sum_1(self):
+        self.assertEqual(square_of_sum(1), 1)
+
+    def test_square_of_sum_5(self):
+        self.assertEqual(square_of_sum(5), 225)
+
+    def test_square_of_sum_100(self):
+        self.assertEqual(square_of_sum(100), 25502500)
+
+    def test_sum_of_squares_1(self):
+        self.assertEqual(sum_of_squares(1), 1)
+
+    def test_sum_of_squares_5(self):
+        self.assertEqual(sum_of_squares(5), 55)
+
+    def test_sum_of_squares_100(self):
+        self.assertEqual(sum_of_squares(100), 338350)
+
+    def test_difference_of_squares_1(self):
+        self.assertEqual(difference_of_squares(1), 0)
+
+    def test_difference_of_squares_5(self):
+        self.assertEqual(difference_of_squares(5), 170)
+
+    def test_difference_of_squares_100(self):
+        self.assertEqual(difference_of_squares(100), 25164150)

python/difference-of-squares/pytest.ini

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+[pytest]
+pythonpath = .
+addopts = --doctest-modules
+markers =
+    task: exercise task/step