[D&D Character] Approaches (#3666)

* [D&D Character] draft approaches

* Added 4 approaches as examples of possible solutions based on the intro.

* Added snippets for the 4 new approaches.

* Modifications to introduction and config json.

* Update exercises/practice/dnd-character/.approaches/loop-and-setattr-in-init/content.md

* Update exercises/practice/dnd-character/.approaches/introduction.md

* Update exercises/practice/dnd-character/.approaches/stand-alone-dice-roll-function/content.md

---------

Co-authored-by: BethanyG <BethanyG@users.noreply.github.com>

Author: colinleach

exercises/practice/dnd-character/.approaches/ability-method/content.md

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+# Use the `ability()` Method to Generate and Return the Dice Rolls
+
+
+```python
+from random import sample
+
+class Character:
+    def __init__(self):
+        self.strength = self.ability()
+        self.dexterity = self.ability()
+        self.constitution = self.ability()
+        self.intelligence = self.ability()
+        self.wisdom = self.ability()
+        self.charisma = self.ability()
+        
+        self.hitpoints = 10 + modifier(self.constitution)
+
+    def ability(self):
+        values = sample(range(1, 7), 4)
+        return sum(values) - min(values)
+        
+def modifier(constitution):
+    return (constitution - 10)//2
+```
+
+
+This approach uses a single `ability()` method to calculate the dice rolls and return an ability value.
+`ability()` is then called in `__init__()` to populate the listed-out character attributes.
+`self.hitpoints` calls the stand-alone `modifier()` function, adding it to 10 for the character's hitpoints attribute.
+
+This approach is valid and passes all the tests.
+However, it will trigger an analyzer comment about there being "too few public methods", since there are no methods for this class beyond the one that calculates attribute values.
+
+
+The "too few" rule encourages you to think about the design of the class: is it worth the effort to create the class if it only holds attribute values for a character?
+What other functionality should this class hold?
+Should you separate dice rolls from ability values?
+Is the class better as a [dataclass][dataclass], with dice roll as a utility function?
+
+None of these (_including the analyzer complaint about too few methods_) is a hard and fast rule or requirement - all are considerations for the class as you build out a larger program.
+
+
+[dataclass]: https://docs.python.org/3/library/dataclasses.html

exercises/practice/dnd-character/.approaches/ability-method/snippet.txt

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+    ...
+    def __init__(self):
+        for ability_type in self.ABILITIES:
+            setattr(self, ability_type, self.ability())
+
+    def ability(self):
+        values = sample(range(1, 7), 4)
+        return sum(values) - min(values)

exercises/practice/dnd-character/.approaches/config.json

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+{
+  "introduction": {
+    "authors": ["colinleach",
+                "BethanyG"],
+    "contributors": []
+  },
+    "approaches": [
+    {
+      "uuid": "952835d1-e9d1-4dc3-b2c2-aad703e8db2e",
+      "slug": "ability-method",
+      "title": "Ability Method",
+      "blurb": "Use one method to generate dice rolls and return ability values.",
+      "authors": ["bethanyg"]
+    },
+    {
+      "uuid": "5022c80c-8ca1-45e4-aa5f-d91bb3f53441",
+      "slug": "dice-roll-static-method",
+      "title": "Dice Roll Static Method",
+      "blurb": "Use a separate static method to conduct dice rolls.",
+      "authors": ["bethanyg"]
+    },
+    {
+      "uuid": "98af6c1d-5ab4-476d-9041-30b8f55e13eb",
+      "slug": "stand-alone-dice-roll-function",
+      "title": "Stand-alone Dice Roll Function",
+      "blurb": "Create a dice roll function outside the Character class.",
+      "authors": ["bethanyg"]
+    },
+    {
+      "uuid": "5dd9d9b0-bfa5-43b2-8e95-787425349fc4",
+      "slug": "loop-and-setattr-in-init",
+      "title": "Loop and setattr in init",
+      "blurb": "Use a tuple of attributes, a loop, and setattr in init to assign ability values.",
+      "authors": ["bethanyg"]
+    }
+  ]
+}

exercises/practice/dnd-character/.approaches/dice-roll-static-method/content.md

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+# Move Dice Rolls Into a Static Method Separate from the `ability` Method
+
+
+```python
+from math import floor
+from random import choice
+
+class Character:
+    def __init__(self):
+        self.strength = Character.dice_rolls()
+        self.dexterity = Character.dice_rolls()
+        self.constitution = Character.dice_rolls()
+        self.intelligence = Character.dice_rolls()
+        self.wisdom = Character.dice_rolls()
+        self.charisma = Character.dice_rolls()
+        
+        self.hitpoints = 10 + modifier(self.constitution)
+
+    def ability(self):
+        return choice([*vars(self).values()])
+        
+    @staticmethod    
+    def dice_rolls():
+        values = sorted(choice(range(1,7)) for dice in range(4))[::-1]
+        return sum(values[:-1])
+
+def modifier(constitution):
+    return floor((constitution - 10)/2)
+```
+
+This approach separates the `ability()` method from a [`static method`][staticmethod] that calculates dice rolls.
+`ability()` returns the value of a randomly chosen character ability using [`random.choice`][random-choice] but does not roll dice or calculate values.
+Instead, `dice_rolls()` handles the rolls/values using [`random.choice`][random-choice] for selection.
+
+The argument for this is that the logic/functionality of rolling dice 4 times and summing the top three values is not really related to a DnD character or their abilities - it is independent and likely useful across a wider scope than just the character class.
+However, it might be tidier to include it in the character class, rather than "clutter" the program or module with an additional stand-alone function.
+Declaring `dice_rolls()` as a static method allows other callers to use the function with or without instantiating a new  `Character` object.
+It also makes it cleaner to maintain, should the method or number of the dice rolls change.
+
+`dice_rolls()` is then called in `__init__()` to populate the listed-out character attributes.
+Note that it needs to be called with the class name: `Character.dice_rolls()`.
+`self.hitpoints` then calls the second stand-alone `modifier()` function, adding it to 10 for the character's `hitpoints` attribute.
+`modifieer()` in this example uses [`math.floor`][math-floor] for calculating the `hitpoints` value.
+
+[math-floor]: https://docs.python.org/3/library/math.html#math.floor
+[random-choice]: https://docs.python.org/3/library/random.html#random.choice
+[staticmethod]: https://docs.python.org/3/library/functions.html#staticmethod

exercises/practice/dnd-character/.approaches/dice-roll-static-method/snippet.txt

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+     ...
+     def ability(self):
+         return choice([*vars(self).values()])
+
+     @staticmethod
+     def dice_roll():
+         values = sample(range(1, 7), 4)
+         return sum(sorted(values, reverse=True)[:-1])