Fix: handle word not in vocabulary error

incorrect_answer_generation.py

@@ -2,10 +2,12 @@
 for generating incorrect alternative
 answers for a given answer
 '''
+import gensim
 import gensim.downloader as api
+from gensim.models import Word2Vec
 from nltk.tokenize import sent_tokenize, word_tokenize
 import random
-
+import numpy as np
 
 class IncorrectAnswerGenerator:
     ''' This class contains the methods
@@ -13,20 +15,43 @@ class IncorrectAnswerGenerator:
     given an answer
     '''
 
-    def __init__(self):
+    def __init__(self, document):
         # model required to fetch similar words
         self.model = api.load("glove-wiki-gigaword-100")
+        self.all_words = []
+        for sent in sent_tokenize(document):
+            self.all_words.extend(word_tokenize(sent))
+        self.all_words = list(set(self.all_words))
 
     def get_all_options_dict(self, answer, num_options):
         ''' This method returns a dict
         of 'num_options' options out of
         which one is correct and is the answer
         '''
-        similar_words = self.model.similar_by_word(answer, topn=15)[::-1]
         options_dict = dict()
+        try:
+            similar_words = self.model.similar_by_word(answer, topn=15)[::-1]
 
-        for i in range(1, num_options + 1):
+            for i in range(1, num_options + 1):
-            options_dict[i] = similar_words[i - 1][0]
+                options_dict[i] = similar_words[i - 1][0]
+
+        except:
+            self.all_sim = []
+            for word in self.all_words:
+                if word not in answer:
+                    try:
+                        self.all_sim.append(
+                            (self.model.similarity(answer, word), word))
+                    except:
+                        self.all_sim.append(
+                            (0.0, word))
+                else:
+                    self.all_sim.append((-1.0, word))
+
+            self.all_sim.sort(reverse=True)
+
+            for i in range(1, num_options+1):
+                options_dict[i] = self.all_sim[i-1][1]
 
         replacement_idx = random.randint(1, num_options)