Implement exercise hangman

config.json

@@ -32,13 +32,13 @@
       ]
     },
     {
-      "uuid": "574d6323-5ff5-4019-9ebe-0067daafba13",
       "slug": "high-scores",
+      "uuid": "574d6323-5ff5-4019-9ebe-0067daafba13",
       "core": true,
       "unlocked_by": null,
       "difficulty": 1,
       "topics": [
-        "control-flow (if-else statements)",
+        "control_flow_if_else_statements",
         "sequences",
         "text_formatting"
       ]
@@ -351,7 +351,6 @@
       ]
     },
     {
-      "uuid": "505e7bdb-e18d-45fd-9849-0bf33492efd9",
       "slug": "run-length-encoding",
       "uuid": "505e7bdb-e18d-45fd-9849-0bf33492efd9",
       "core": false,
@@ -1332,6 +1331,16 @@
         "trees"
       ]
     },
+    {
+      "slug": "hangman",
+      "uuid": "adad6be5-855d-4d61-b14a-22e468ba5b44",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 5,
+      "topics": [
+        "strings"
+      ]
+    },
     {
       "slug": "custom-set",
       "uuid": "bb07c236-062c-2980-483a-a221e4724445dcd6f32",
@@ -1402,15 +1411,15 @@
       ]
     },
     {
-        "slug": "dnd-character",
-        "uuid": "58625685-b5cf-4e8a-b3aa-bff54da0689d",
-        "core": false,
-        "unlocked_by": null,
-        "difficulty": 1,
-        "topics": [
-            "randomness",
-            "integers"
-        ]
+      "slug": "dnd-character",
+      "uuid": "58625685-b5cf-4e8a-b3aa-bff54da0689d",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 1,
+      "topics": [
+        "integers",
+        "randomness"
+      ]
     },
     {
       "slug": "retree",
@@ -1432,8 +1441,8 @@
       "unlocked_by": null,
       "difficulty": 2,
       "topics": [
-          "conditionals",
-          "math"
+        "conditionals",
+        "math"
       ]
     },
     {

exercises/hangman/.meta/hints.md

@@ -0,0 +1,3 @@
+## Hints
+
+Please ignore the part regarding FRP library, a third party library is not required for this exercise.

exercises/hangman/README.md

@@ -0,0 +1,68 @@
+# Hangman
+
+Implement the logic of the hangman game using functional reactive programming.
+
+[Hangman][] is a simple word guessing game.
+
+[Functional Reactive Programming][frp] is a way to write interactive
+programs. It differs from the usual perspective in that instead of
+saying "when the button is pressed increment the counter", you write
+"the value of the counter is the sum of the number of times the button
+is pressed."
+
+Implement the basic logic behind hangman using functional reactive
+programming.  You'll need to install an FRP library for this, this will
+be described in the language/track specific files of the exercise.
+
+[Hangman]: https://en.wikipedia.org/wiki/Hangman_%28game%29
+[frp]: https://en.wikipedia.org/wiki/Functional_reactive_programming
+
+## Hints
+
+Please ignore the part regarding FRP library, a third party library is not required for this exercise.
+
+
+## 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 hangman_test.py`
+- Python 3.4+: `pytest hangman_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 hangman_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/hangman` 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).
+
+## Submitting Incomplete Solutions
+
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.

exercises/hangman/example.py

@@ -0,0 +1,50 @@
+STATUS_WIN = "win"
+STATUS_LOSE = "lose"
+STATUS_ONGOING = "ongoing"
+
+
+class Hangman:
+    def __init__(self, word):
+        self.remainingGuesses = 9
+        self.status = STATUS_ONGOING
+        self.word = word
+        self.masked_word = ''
+        self.guesses = []
+        for i in self.word:
+            self.masked_word += '_'
+
+    def guess(self, char):
+        if self.status != STATUS_ONGOING:
+            raise ValueError("Game already ended, you " + self.status)
+
+        self.update_remaining_guesses(char)
+        self.update_masked_word()
+        self.update_status()
+
+    def update_masked_word(self):
+        self.masked_word = ''
+        for i in self.word:
+            if i not in self.guesses:
+                self.masked_word += '_'
+            else:
+                self.masked_word += i
+
+    def update_remaining_guesses(self, char):
+        if char not in self.word or char in self.guesses:
+            self.remainingGuesses -= 1
+        else:
+            self.guesses.append(char)
+
+    def update_status(self):
+        if self.masked_word == self.word:
+            self.status = STATUS_WIN
+        elif self.remainingGuesses < 0:
+            self.status = STATUS_LOSE
+        else:
+            self.status = STATUS_ONGOING
+
+    def get_masked_word(self):
+        return self.masked_word
+
+    def get_status(self):
+        return self.status

exercises/hangman/hangman.py

@@ -0,0 +1,20 @@
+# Game status categories
+# Change the values as you see fit
+STATUS_WIN = "win"
+STATUS_LOSE = "lose"
+STATUS_ONGOING = "ongoing"
+
+
+class Hangman(object):
+    def __init__(self, word):
+        self.remainingGuesses = 9
+        self.status = STATUS_ONGOING
+
+    def guess(self, char):
+        pass
+
+    def get_masked_word(self):
+        pass
+
+    def get_status(self):
+        pass

exercises/hangman/hangman_test.py

@@ -0,0 +1,98 @@
+import unittest
+
+import hangman
+from hangman import Hangman
+
+
+# Tests adapted from csharp//hangman/HangmanTest.cs
+
+class HangmanTests(unittest.TestCase):
+    def test_initially_9_failures_are_allowed(self):
+        game = Hangman('foo')
+        self.assertEqual(game.get_status(), hangman.STATUS_ONGOING)
+        self.assertEqual(game.remainingGuesses, 9)
+
+    def test_initially_no_letters_are_guessed(self):
+        game = Hangman('foo')
+
+        self.assertEqual(game.get_masked_word(), '___')
+
+    def test_after_10_failures_the_game_is_over(self):
+        game = Hangman('foo')
+
+        for i in range(10):
+            game.guess('x')
+
+        self.assertEqual(game.get_status(), hangman.STATUS_LOSE)
+        with self.assertRaisesWithMessage(ValueError):
+            game.guess('x')
+
+    def test_feeding_a_correct_letter_removes_underscores(self):
+        game = Hangman('foobar')
+
+        game.guess('b')
+        self.assertEqual(game.get_status(), hangman.STATUS_ONGOING)
+        self.assertEqual(game.remainingGuesses, 9)
+        self.assertEqual(game.get_masked_word(), '___b__')
+
+        game.guess('o')
+        self.assertEqual(game.get_status(), hangman.STATUS_ONGOING)
+        self.assertEqual(game.remainingGuesses, 9)
+        self.assertEqual(game.get_masked_word(), '_oob__')
+
+    def test_feeding_a_correct_letter_twice_counts_as_a_failure(self):
+        game = Hangman('foobar')
+
+        game.guess('b')
+        self.assertEqual(game.get_status(), hangman.STATUS_ONGOING)
+        self.assertEqual(game.remainingGuesses, 9)
+        self.assertEqual(game.get_masked_word(), '___b__')
+
+        game.guess('b')
+        self.assertEqual(game.get_status(), hangman.STATUS_ONGOING)
+        self.assertEqual(game.remainingGuesses, 8)
+        self.assertEqual(game.get_masked_word(), '___b__')
+
+    def test_getting_all_the_letters_right_makes_for_a_win(self):
+        game = Hangman('hello')
+
+        game.guess('b')
+        self.assertEqual(game.get_status(), hangman.STATUS_ONGOING)
+        self.assertEqual(game.remainingGuesses, 8)
+        self.assertEqual(game.get_masked_word(), '_____')
+
+        game.guess('e')
+        self.assertEqual(game.get_status(), hangman.STATUS_ONGOING)
+        self.assertEqual(game.remainingGuesses, 8)
+        self.assertEqual(game.get_masked_word(), '_e___')
+
+        game.guess('l')
+        self.assertEqual(game.get_status(), hangman.STATUS_ONGOING)
+        self.assertEqual(game.remainingGuesses, 8)
+        self.assertEqual(game.get_masked_word(), '_ell_')
+
+        game.guess('o')
+        self.assertEqual(game.get_status(), hangman.STATUS_ONGOING)
+        self.assertEqual(game.remainingGuesses, 8)
+        self.assertEqual(game.get_masked_word(), '_ello')
+
+        game.guess('h')
+        self.assertEqual(game.get_status(), hangman.STATUS_WIN)
+        self.assertEqual(game.get_masked_word(), 'hello')
+
+        with self.assertRaisesWithMessage(ValueError):
+            game.guess('x')
+
+    # Utility functions
+    def setUp(self):
+        try:
+            self.assertRaisesRegex
+        except AttributeError:
+            self.assertRaisesRegex = self.assertRaisesRegexp
+
+    def assertRaisesWithMessage(self, exception):
+        return self.assertRaisesRegex(exception, r".+")
+
+
+if __name__ == '__main__':
+    unittest.main()