Minor updates

spellchecker/spellchecker.py

@@ -509,11 +509,14 @@ def remove_by_threshold(self, threshold: int = 5) -> None:
 
     def _update_dictionary(self) -> None:
         """Update the word frequency object"""
-        self._longest_word_length = 0
+        if not self._dictionary:
+            self._longest_word_length = 0
+            self._total_words = 0
+            self._unique_words = 0
+            self._letters = set()
+            return
+        keys = self._dictionary.keys()
+        self._longest_word_length = max(map(len, keys))
         self._total_words = sum(self._dictionary.values())
-        self._unique_words = len(self._dictionary.keys())
-        self._letters = set()
-        for key in self._dictionary:
-            if len(key) > self._longest_word_length:
-                self._longest_word_length = len(key)
-            self._letters.update(key)
+        self._unique_words = len(keys)
+        self._letters = set().union(*keys)

spellchecker/utils.py

@@ -25,7 +25,7 @@ def decorator_wrapper(func):
         def test_inner(*args, **kwargs):
             if [int(x) for x in version.split(".")] <= [int(x) for x in __version__.split(".")]:
                 msg = (
-                    f"The function {func.__name__} must be fully removed as it is depricated"
+                    f"The function {func.__name__} must be fully removed as it is deprecated"
                     f" and must be removed by version {version}"
                 )
                 raise AssertionError(msg)
@@ -76,7 +76,7 @@ def ensure_unicode(value: KeyT, encoding: str = "utf-8") -> str:
     if isinstance(value, bytes):
         return value.decode(encoding)
     elif isinstance(value, list):
-        raise TypeError(f"The provided value {value} is a not of type str or bytes")
+        raise TypeError(f"The provided value {value} is not of type str or bytes")
     return value