diff --git a/wordle.py b/wordle.py
index dca2c1b..9d90b90 100644
--- a/wordle.py
+++ b/wordle.py
@@ -11,36 +11,91 @@ WORDLE_LENGTH = 5
 
 class LetterResult(Enum):
     """Is an individual letter in a word in the result?"""
-    CORRECT = 'C'
-    MOVE = 'M'
-    INCORRECT = 'I'
-    UNKNOWN = 'U'
+
+    CORRECT = "C"
+    MOVE = "M"
+    INCORRECT = "I"
+    UNKNOWN = "U"
 
 
 class InvalidWord(Exception):
     """Thrown when an input word is not a valid Wordle."""
+
     pass
 
 
 _wordle_dictionary = set()
 
 
-_invalid_words = set([
-                      'staia', 'erept', 'boily', 'bolty', 'pindy', 'hyrse', 'hirse', 'retan', 'sisel',
-                      'skeel', 'telae', 'genae', 'beata', 'beala', 'macco', 'beele', 'divet', 'vedet',
-                      'stail', 'roter', 'fikie', 'muang', 'nurry', 'arara', 'araru', 'araua', 'arawa',
-                      'mitra', 'gotra', 'whaly', 'whalm', 'doray', 'korah', 'caroa', 'carlo', 'carot',
-                      'carum', 'theet', 'tebet', 'ghole', 'odell', 'sussy', 'bayal', 'balak', 'katat',
-                      'batak', 'bruke', 'uninn', 'undig', 'unkin', 'quito', 'petro', 'amala',
-                      ])
+_invalid_words = set(
+    [
+        "amala",
+        "arara",
+        "araru",
+        "araua",
+        "arawa",
+        "balak",
+        "batak",
+        "bayal",
+        "beala",
+        "beata",
+        "beele",
+        "boily",
+        "bolty",
+        "bruke",
+        "carlo",
+        "caroa",
+        "carot",
+        "carum",
+        "divet",
+        "doray",
+        "erept",
+        "fikie",
+        "genae",
+        "ghole",
+        "gotra",
+        "hirse",
+        "hyrse",
+        "katat",
+        "korah",
+        "macco",
+        "mitra",
+        "muang",
+        "nurry",
+        "odell",
+        "odell",
+        "petro",
+        "pindy",
+        "quito",
+        "retan",
+        "roter",
+        "sisel",
+        "skeel",
+        "staia",
+        "stail",
+        "sussy",
+        "tebet",
+        "telae",
+        "theet",
+        "undig",
+        "uninn",
+        "unkin",
+        "vedet",
+        "whalm",
+        "whaly",
+    ]
+)
 
 
 def dictionary():
     if not _wordle_dictionary:
-        with open('words_alpha.txt') as word_file:
+        with open("words_alpha.txt") as word_file:
             all_words = word_file.read().split()
         _wordle_dictionary.update(
-            filter(lambda w: len(w) == WORDLE_LENGTH and w not in _invalid_words, all_words))
+            filter(
+                lambda w: len(w) == WORDLE_LENGTH and w not in _invalid_words, all_words
+            )
+        )
 
     return _wordle_dictionary
 
@@ -82,12 +137,12 @@ def grade_word(target, guess):
 
 def display_result(result, text):
     opening = {
-        LetterResult.CORRECT: '\033[92m',
-        LetterResult.MOVE: '\033[33m',
-        LetterResult.INCORRECT: '\033[36m',
-        LetterResult.UNKNOWN: '',
+        LetterResult.CORRECT: "\033[92m",
+        LetterResult.MOVE: "\033[33m",
+        LetterResult.INCORRECT: "\033[36m",
+        LetterResult.UNKNOWN: "",
     }
-    closing = '\033[0m'
+    closing = "\033[0m"
 
     return f"{opening[result]}{text}{closing}"
 
@@ -102,11 +157,13 @@ def success_result(result):
 
 def analyze_dictionary(wordle_dictionary):
     # Word Position, Letter: Count
-    position_matches = [defaultdict(int),
-                        defaultdict(int),
-                        defaultdict(int),
-                        defaultdict(int),
-                        defaultdict(int)]
+    position_matches = [
+        defaultdict(int),
+        defaultdict(int),
+        defaultdict(int),
+        defaultdict(int),
+        defaultdict(int),
+    ]
 
     # Letter: Count
     word_matches = defaultdict(int)
@@ -118,7 +175,7 @@ def analyze_dictionary(wordle_dictionary):
 
         for index in range(len(word)):
             letter = word[index]
-            assert (letter in string.ascii_lowercase)
+            assert letter in string.ascii_lowercase
             position_matches[index][letter] += 1
 
     return position_matches, word_matches
@@ -156,8 +213,7 @@ def scored_words(wordle_dictionary=dictionary()):
     return [(word, scored_words[word]) for word in result]
 
 
-class Constraints():
-
+class Constraints:
     def __init__(self):
         # Array of known letters in result with None for unknown.
         self.correct = [None] * WORDLE_LENGTH
@@ -170,7 +226,6 @@ class Constraints():
 
     # List of LetterResult values.
     def update_graded(self, guess, grade):
-
         guess = guess.lower()
 
         new_count = defaultdict(int)
@@ -192,7 +247,6 @@ class Constraints():
             self.count[letter] = max(c, self.count[letter])
 
     def matches(self, guess):
-
         counts = defaultdict(int)
 
         # All known correct letters in place.
@@ -222,10 +276,18 @@ def filter_dictionary(constraints, wordle_dictionary=dictionary()):
     return set(filter(lambda w: constraints.matches(w), wordle_dictionary))
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     constraints = Constraints()
-    constraints.update_graded('cares', [LetterResult.INCORRECT, LetterResult.INCORRECT,
-                              LetterResult.INCORRECT, LetterResult.INCORRECT, LetterResult.INCORRECT])
+    constraints.update_graded(
+        "cares",
+        [
+            LetterResult.INCORRECT,
+            LetterResult.INCORRECT,
+            LetterResult.INCORRECT,
+            LetterResult.INCORRECT,
+            LetterResult.INCORRECT,
+        ],
+    )
 
     valid_words = filter_dictionary(constraints)