Add morphy modes to WordNetLemmatizer

Author: ekaf

nltk/stem/wordnet.py

@@ -3,6 +3,7 @@
 # Copyright (C) 2001-2023 NLTK Project
 # Author: Steven Bird <[email protected]>
 #         Edward Loper <[email protected]>
+#         Eric Kafe <[email protected]>
 # URL: <https://www.nltk.org/>
 # For license information, see LICENSE.TXT
 
@@ -13,9 +14,45 @@ class WordNetLemmatizer:
     """
     WordNet Lemmatizer
 
-    Lemmatize by picking the shortest of the possible lemmas,
-    using the wordnet corpus reader's built-in _morphy function.
-    Returns the input word unchanged if it cannot be found in WordNet.
+    Provides 3 lemmatizer modes:
+
+    1. _morphy() is an alias to WordNet's _morphy lemmatizer.
+    It returns a list of all lemmas found in WordNet.
+
+    >>> wnl = WordNetLemmatizer()
+    >>> print(wnl._morphy('us', 'n'))
+    ['us', 'u']
+
+    2. morphy() is a restrictive wrapper around _morphy().
+    It returns the first lemma found in WordNet,
+    or None if no lemma is found.
+
+    >>> print(wnl.morphy('us', 'n'))
+    us
+
+    >>> print(wnl.morphy('catss'))
+    None
+
+    3. lemmatize() is a permissive wrapper around _morphy().
+    It returns the shortest lemma found in WordNet,
+    or the input string unchanged if nothing is found.
+
+    >>> print(wnl.lemmatize('us', 'n'))
+    u
+
+    >>> print(wnl.lemmatize('Anythinggoeszxcv'))
+    Anythinggoeszxcv
+
+    """
+
+    morphy = wn.morphy
+
+    _morphy = wn._morphy
+
+    def lemmatize(self, word: str, pos: str = "n") -> str:
+        """Lemmatize `word` by picking the shortest of the possible lemmas,
+        using the wordnet corpus reader's built-in _morphy function.
+        Returns the input word unchanged if it cannot be found in WordNet.
 
         >>> from nltk.stem import WordNetLemmatizer
         >>> wnl = WordNetLemmatizer()
@@ -29,12 +66,6 @@ class WordNetLemmatizer:
         abacus
         >>> print(wnl.lemmatize('hardrock'))
         hardrock
-    """
-
-    def lemmatize(self, word: str, pos: str = "n") -> str:
-        """Lemmatize `word` by picking the shortest of the possible lemmas,
-        using the wordnet corpus reader's built-in _morphy function.
-        Returns the input word unchanged if it cannot be found in WordNet.
 
         :param word: The input word to lemmatize.
         :type word: str
@@ -44,7 +75,7 @@ def lemmatize(self, word: str, pos: str = "n") -> str:
         :type pos: str
         :return: The shortest lemma of `word`, for the given `pos`.
         """
-        lemmas = wn._morphy(word, pos)
+        lemmas = self._morphy(word, pos)
         return min(lemmas, key=len) if lemmas else word
 
     def __repr__(self):