Add wv property to KeyedVectors (for backward compatibility). Fix p…

…iskvorky#1882 (piskvorky#1884)

* adds test for `wv` property

* adds `wv` property to KeyedVectors class

gensim/models/keyedvectors.py

@@ -198,6 +198,11 @@ def __init__(self, vector_size):
         self.vectors_norm = None
         self.index2word = []
 
+    @property
+    @deprecated("Attribute will be removed in 4.0.0, use self instead")
+    def wv(self):
+        return self
+
     @property
     def index2entity(self):
         return self.index2word

gensim/test/test_keyedvectors.py

@@ -149,6 +149,10 @@ def test_rank(self):
         self.assertEqual(self.vectors.rank('war', 'war'), 1)
         self.assertEqual(self.vectors.rank('war', 'terrorism'), 3)
 
+    def test_wv_property(self):
+        """Test that the deprecated `wv` property returns `self`. To be removed in v4.0.0."""
+        self.assertTrue(self.vectors is self.vectors.wv)
+
 
 if __name__ == '__main__':
     logging.basicConfig(format='%(asctime)s : %(levelname)s : %(message)s', level=logging.DEBUG)