rot cipher, difference of squares exercises

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

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+{"track":"python","exercise":"difference-of-squares","id":"79021d92f5b24650af12a464a9f6e9d6","url":"https://exercism.io/my/solutions/79021d92f5b24650af12a464a9f6e9d6","handle":"Xevion","is_requester":true,"auto_approve":false}

python/difference-of-squares/README.md

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+# Difference Of Squares
+
+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.
+
+## Exception messages
+
+Sometimes it is necessary to raise an exception. When you do this, you should include a meaningful error message to
+indicate what the source of the error is. This makes your code more readable and helps significantly with debugging. Not
+every exercise will require you to raise an exception, but for those that do, the tests will only pass if you include
+a message.
+
+To raise a message with an exception, just write it as an argument to the exception type. For example, instead of
+`raise Exception`, you should write:
+
+```python
+raise Exception("Meaningful message indicating the source of the error")
+```
+
+## Running the tests
+
+To run the tests, run the appropriate command below ([why they are different](https://github.com/pytest-dev/pytest/issues/1629#issue-161422224)):
+
+- Python 2.7: `py.test difference_of_squares_test.py`
+- Python 3.4+: `pytest difference_of_squares_test.py`
+
+Alternatively, you can tell Python to run the pytest module (allowing the same command to be used regardless of Python version):
+`python -m pytest difference_of_squares_test.py`
+
+### Common `pytest` options
+
+- `-v` : enable verbose output
+- `-x` : stop running tests on first failure
+- `--ff` : run failures from previous test before running other test cases
+
+For other options, see `python -m pytest -h`
+
+## Submitting Exercises
+
+Note that, when trying to submit an exercise, make sure the solution is in the `$EXERCISM_WORKSPACE/python/difference-of-squares` directory.
+
+You can find your Exercism workspace by running `exercism debug` and looking for the line that starts with `Workspace`.
+
+For more detailed information about running tests, code style and linting,
+please see [Running the Tests](http://exercism.io/tracks/python/tests).
+
+## Source
+
+Problem 6 at Project Euler [http://projecteuler.net/problem=6](http://projecteuler.net/problem=6)
+
+## Submitting Incomplete Solutions
+
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.

python/difference-of-squares/difference_of_squares.py

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+def square_of_sum(number):
+    return sum(range(1, number + 1)) ** 2
+
+
+def sum_of_squares(number):
+    return sum(i ** 2 for i in range(1, number + 1))
+
+
+def difference_of_squares(number):
+    return abs(square_of_sum(number) - sum_of_squares(number))

python/difference-of-squares/difference_of_squares_test.py

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+import unittest
+
+from difference_of_squares import (
+    difference_of_squares,
+    square_of_sum,
+    sum_of_squares
+)
+
+
+# Tests adapted from `problem-specifications//canonical-data.json` @ v1.2.0
+
+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)
+
+
+if __name__ == '__main__':
+    unittest.main()

python/rotational-cipher/.exercism/metadata.json

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+{"track":"python","exercise":"rotational-cipher","id":"83ee13c77e1d4de898c100f544771cf7","url":"https://exercism.io/my/solutions/83ee13c77e1d4de898c100f544771cf7","handle":"Xevion","is_requester":true,"auto_approve":false}

python/rotational-cipher/README.md

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+# Rotational Cipher
+
+Create an implementation of the rotational cipher, also sometimes called the Caesar cipher.
+
+The Caesar cipher is a simple shift cipher that relies on
+transposing all the letters in the alphabet using an integer key
+between `0` and `26`. Using a key of `0` or `26` will always yield
+the same output due to modular arithmetic. The letter is shifted
+for as many values as the value of the key.
+
+The general notation for rotational ciphers is `ROT + <key>`.
+The most commonly used rotational cipher is `ROT13`.
+
+A `ROT13` on the Latin alphabet would be as follows:
+
+```text
+Plain:  abcdefghijklmnopqrstuvwxyz
+Cipher: nopqrstuvwxyzabcdefghijklm
+```
+
+It is stronger than the Atbash cipher because it has 27 possible keys, and 25 usable keys.
+
+Ciphertext is written out in the same formatting as the input including spaces and punctuation.
+
+## Examples
+
+- ROT5  `omg` gives `trl`
+- ROT0  `c` gives `c`
+- ROT26 `Cool` gives `Cool`
+- ROT13 `The quick brown fox jumps over the lazy dog.` gives `Gur dhvpx oebja sbk whzcf bire gur ynml qbt.`
+- ROT13 `Gur dhvpx oebja sbk whzcf bire gur ynml qbt.` gives `The quick brown fox jumps over the lazy dog.`
+
+## Exception messages
+
+Sometimes it is necessary to raise an exception. When you do this, you should include a meaningful error message to
+indicate what the source of the error is. This makes your code more readable and helps significantly with debugging. Not
+every exercise will require you to raise an exception, but for those that do, the tests will only pass if you include
+a message.
+
+To raise a message with an exception, just write it as an argument to the exception type. For example, instead of
+`raise Exception`, you should write:
+
+```python
+raise Exception("Meaningful message indicating the source of the error")
+```
+
+## Running the tests
+
+To run the tests, run the appropriate command below ([why they are different](https://github.com/pytest-dev/pytest/issues/1629#issue-161422224)):
+
+- Python 2.7: `py.test rotational_cipher_test.py`
+- Python 3.4+: `pytest rotational_cipher_test.py`
+
+Alternatively, you can tell Python to run the pytest module (allowing the same command to be used regardless of Python version):
+`python -m pytest rotational_cipher_test.py`
+
+### Common `pytest` options
+
+- `-v` : enable verbose output
+- `-x` : stop running tests on first failure
+- `--ff` : run failures from previous test before running other test cases
+
+For other options, see `python -m pytest -h`
+
+## Submitting Exercises
+
+Note that, when trying to submit an exercise, make sure the solution is in the `$EXERCISM_WORKSPACE/python/rotational-cipher` directory.
+
+You can find your Exercism workspace by running `exercism debug` and looking for the line that starts with `Workspace`.
+
+For more detailed information about running tests, code style and linting,
+please see [Running the Tests](http://exercism.io/tracks/python/tests).
+
+## Source
+
+Wikipedia [https://en.wikipedia.org/wiki/Caesar_cipher](https://en.wikipedia.org/wiki/Caesar_cipher)
+
+## Submitting Incomplete Solutions
+
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.

python/rotational-cipher/rotational_cipher.py

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+from string import ascii_letters
+
+def rotate(text, key):
+    key = key % 26
+    return text.translate(str.maketrans(ascii_letters, ascii_letters[key:26] + ascii_letters[:key] + ascii_letters[26+key:] + ascii_letters[26:26 + key]))

python/rotational-cipher/rotational_cipher_test.py

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+import unittest
+
+import rotational_cipher
+
+
+# Tests adapted from `problem-specifications//canonical-data.json` @ v1.2.0
+
+class RotationalCipherTest(unittest.TestCase):
+    def test_rotate_a_by_0(self):
+        self.assertEqual(rotational_cipher.rotate('a', 0), 'a')
+
+    def test_rotate_a_by_1(self):
+        self.assertEqual(rotational_cipher.rotate('a', 1), 'b')
+
+    def test_rotate_a_by_26(self):
+        self.assertEqual(rotational_cipher.rotate('a', 26), 'a')
+
+    def test_rotate_m_by_13(self):
+        self.assertEqual(rotational_cipher.rotate('m', 13), 'z')
+
+    def test_rotate_n_by_13_with_wrap_around_alphabet(self):
+        self.assertEqual(rotational_cipher.rotate('n', 13), 'a')
+
+    def test_rotate_capital_letters(self):
+        self.assertEqual(rotational_cipher.rotate('OMG', 5), 'TRL')
+
+    def test_rotate_spaces(self):
+        self.assertEqual(rotational_cipher.rotate('O M G', 5), 'T R L')
+
+    def test_rotate_numbers(self):
+        self.assertEqual(
+            rotational_cipher.rotate('Testing 1 2 3 testing', 4),
+            'Xiwxmrk 1 2 3 xiwxmrk')
+
+    def test_rotate_punctuation(self):
+        self.assertEqual(
+            rotational_cipher.rotate("Let's eat, Grandma!", 21),
+            "Gzo'n zvo, Bmviyhv!")
+
+    def test_rotate_all_letters(self):
+        self.assertEqual(
+            rotational_cipher.rotate("The quick brown fox jumps"
+                                     " over the lazy dog.", 13),
+            "Gur dhvpx oebja sbk whzcf bire gur ynml qbt.")
+
+
+if __name__ == '__main__':
+    unittest.main()