better fix

Author: l1ebl

mathics/builtin/natlang.py

@@ -103,38 +103,31 @@ def generator(doc):
 
     return forms
 
+# the following two may only be accessed after_WordNetBuiltin._load_wordnet has
+# been called.
+
+_wordnet_pos_to_type = {}
+_wordnet_type_to_pos = {}
+
 try:
     import nltk
 
-    _lazy_wordnet_pos_to_type = {}
-    _lazy_wordnet_type_to_pos = {}
-
-    def _wordnet_pos_to_type(p):
-        if not _lazy_wordnet_pos_to_type:
-            _lazy_wordnet_pos_to_type.update({
-                nltk.corpus.wordnet.VERB: 'Verb',
-                nltk.corpus.wordnet.NOUN: 'Noun',
-                nltk.corpus.wordnet.ADJ: 'Adjective',
-                nltk.corpus.wordnet.ADJ_SAT: 'Adjective',
-                nltk.corpus.wordnet.ADV: 'Adverb',
-            })
-        return _lazy_wordnet_pos_to_type[p]
-
-    def _wordnet_type_to_pos(t):
-        if not _lazy_wordnet_type_to_pos:
-            _lazy_wordnet_type_to_pos.update({
-                'Verb': [nltk.corpus.wordnet.VERB],
-                'Noun': [nltk.corpus.wordnet.NOUN],
-                'Adjective': [nltk.corpus.wordnet.ADJ, nltk.corpus.wordnet.ADJ_SAT],
-                'Adverb': [nltk.corpus.wordnet.ADV],
-            })
-        return _lazy_wordnet_type_to_pos[t]
-except (ImportError, LookupError):
-    def _wordnet_pos_to_type(p):
-        raise ValueError('Needed NLTK corpora are not installed.')
-
-    def _wordnet_type_to_pos(t):
-        raise ValueError('Needed NLTK corpora are not installed.')
+    def _init_nltk_maps():
+        _wordnet_pos_to_type.update({
+            nltk.corpus.wordnet.VERB: 'Verb',
+            nltk.corpus.wordnet.NOUN: 'Noun',
+            nltk.corpus.wordnet.ADJ: 'Adjective',
+            nltk.corpus.wordnet.ADJ_SAT: 'Adjective',
+            nltk.corpus.wordnet.ADV: 'Adverb',
+        })
+        _wordnet_type_to_pos.update({
+            'Verb': [nltk.corpus.wordnet.VERB],
+            'Noun': [nltk.corpus.wordnet.NOUN],
+            'Adjective': [nltk.corpus.wordnet.ADJ, nltk.corpus.wordnet.ADJ_SAT],
+            'Adverb': [nltk.corpus.wordnet.ADV],
+        })
+except ImportError:
+    pass
 
 try:
     import spacy
@@ -782,6 +775,7 @@ def _language_name(self, evaluation, options):
     def _init_wordnet(self, evaluation, language_name, language_code):
         try:
             wordnet_resource = nltk.data.find('corpora/wordnet')
+            _init_nltk_maps()
         except LookupError:
             evaluation.message(self.get_name(), 'package', 'wordnet')
             return None
@@ -852,7 +846,7 @@ def containers():
             for lemma in WordProperty._synonymous_lemmas(syn):
                 yield lemma.name()
 
-        return what, _wordnet_pos_to_type(pos), containers
+        return what, _wordnet_pos_to_type[pos], containers
 
     @staticmethod
     def syn(syn, wordnet, language_code):
@@ -1009,7 +1003,7 @@ def _words(self, language_name, type, evaluation):
                 if type == 'All':
                     filtered_pos = [None]
                 else:
-                    filtered_pos = _wordnet_type_to_pos(type)
+                    filtered_pos = _wordnet_type_to_pos[type]
                 words = []
                 for pos in filtered_pos:
                     words.extend(list(wordnet.all_lemma_names(pos, language_code)))
@@ -1083,7 +1077,7 @@ def _parts_of_speech(self, py_word, wordnet, language_code):
         if not parts:
             return Expression('Missing', 'NotAvailable')
         else:
-            return Expression('List', *[String(s) for s in sorted([_wordnet_pos_to_type(p) for p in parts])])
+            return Expression('List', *[String(s) for s in sorted([_wordnet_pos_to_type[p] for p in parts])])
 
     def _property(self, word, py_property, py_form, evaluation, options):
         if py_property == 'PorterStem':