check the length of entities and probabilities vector + unit test

spacy/kb.pyx

@@ -36,11 +36,18 @@ cdef class KnowledgeBase:
     def add_alias(self, unicode alias, entities, probabilities):
         """For a given alias, add its potential entities and prior probabilies to the KB."""
 
+        # Throw an error if the length of entities and probabilities are not the same
+        if not len(entities) == len(probabilities):
+            raise ValueError("The vectors for entities and probabilities for alias '" + alias
+                             + "' should have equal length, but found "
+                             + str(len(entities)) + " and " + str(len(probabilities)) + "respectively.")
+
+
         # Throw an error if the probabilities sum up to more than 1
         prob_sum = sum(probabilities)
         if prob_sum > 1:
             raise ValueError("The sum of prior probabilities for alias '" + alias + "' should not exceed 1, "
-                                                                                    "but found " + str(prob_sum))
+                             + "but found " + str(prob_sum))
 
         cdef hash_t alias_hash = self.strings.add(alias)
 
@@ -63,9 +70,6 @@ cdef class KnowledgeBase:
             entry_indices.push_back(int(entry_index))
             probs.push_back(float(prob))
 
-        # TODO: check sum(probabilities) <= 1
-        # TODO: check len(entities) == len(probabilities)
-
         self.c_add_aliases(alias_key=alias_hash, entry_indices=entry_indices, probs=probs)
 
 

spacy/tests/pipeline/test_el.py

@@ -49,3 +49,17 @@ def test_kb_invalid_probabilities():
     with pytest.raises(ValueError):
         mykb.add_alias(alias="douglassss", entities=["Q2", "Q3"], probabilities=[0.8, 0.4])
 
+
+def test_kb_invalid_combination():
+    """Test the invalid construction of a KB with non-matching entity and probability lists"""
+    mykb = KnowledgeBase()
+
+    # adding entities
+    mykb.add_entity(entity_id="Q1", prob=0.9)
+    mykb.add_entity(entity_id="Q2", prob=0.2)
+    mykb.add_entity(entity_id="Q3", prob=0.5)
+
+    # adding aliases - should fail because the entities and probabilities vectors are not of equal length
+    with pytest.raises(ValueError):
+        mykb.add_alias(alias="douglassss", entities=["Q2", "Q3"], probabilities=[0.3, 0.4, 0.1])
+