Python: isogram

python/isogram/.exercism/metadata.json

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+{"track":"python","exercise":"isogram","id":"3a1d2802f4914a84830f6e577eecb6ce","url":"https://exercism.io/my/solutions/3a1d2802f4914a84830f6e577eecb6ce","handle":"DmitryKokorin","is_requester":true,"auto_approve":false}

python/isogram/README.md

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+# Isogram
+
+Determine if a word or phrase is an isogram.
+
+An isogram (also known as a "nonpattern word") is a word or phrase without a repeating letter, however spaces and hyphens are allowed to appear multiple times.
+
+Examples of isograms:
+
+- lumberjacks
+- background
+- downstream
+- six-year-old
+
+The word *isograms*, however, is not an isogram, because the s repeats.
+
+
+## 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 `pytest isogram_test.py`
+
+Alternatively, you can tell Python to run the pytest module:
+`python -m pytest isogram_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/isogram` 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/Isogram](https://en.wikipedia.org/wiki/Isogram)
+
+## Submitting Incomplete Solutions
+
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.

python/isogram/isogram.py

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+def is_isogram(string):
+
+    seen_chars = set()
+
+    for ch in string.lower():
+        if not ch.isalpha():
+            continue
+
+        if ch in seen_chars:
+            return False
+
+        seen_chars.add(ch)
+
+    return True

python/isogram/isogram_test.py

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+import unittest
+
+from isogram import is_isogram
+
+# Tests adapted from `problem-specifications//canonical-data.json`
+
+
+class IsogramTest(unittest.TestCase):
+    def test_empty_string(self):
+        self.assertIs(is_isogram(""), True)
+
+    def test_isogram_with_only_lower_case_characters(self):
+        self.assertIs(is_isogram("isogram"), True)
+
+    def test_word_with_one_duplicated_character(self):
+        self.assertIs(is_isogram("eleven"), False)
+
+    def test_word_with_one_duplicated_character_from_the_end_of_the_alphabet(self):
+        self.assertIs(is_isogram("zzyzx"), False)
+
+    def test_longest_reported_english_isogram(self):
+        self.assertIs(is_isogram("subdermatoglyphic"), True)
+
+    def test_word_with_duplicated_character_in_mixed_case(self):
+        self.assertIs(is_isogram("Alphabet"), False)
+
+    def test_word_with_duplicated_character_in_mixed_case_lowercase_first(self):
+        self.assertIs(is_isogram("alphAbet"), False)
+
+    def test_hypothetical_isogrammic_word_with_hyphen(self):
+        self.assertIs(is_isogram("thumbscrew-japingly"), True)
+
+    def test_hypothetical_word_with_duplicated_character_following_hyphen(self):
+        self.assertIs(is_isogram("thumbscrew-jappingly"), False)
+
+    def test_isogram_with_duplicated_hyphen(self):
+        self.assertIs(is_isogram("six-year-old"), True)
+
+    def test_made_up_name_that_is_an_isogram(self):
+        self.assertIs(is_isogram("Emily Jung Schwartzkopf"), True)
+
+    def test_duplicated_character_in_the_middle(self):
+        self.assertIs(is_isogram("accentor"), False)
+
+    def test_same_first_and_last_characters(self):
+        self.assertIs(is_isogram("angola"), False)
+
+
+if __name__ == "__main__":
+    unittest.main()