Fix issue #241: Wrong datatype in error message (#242)

* Fix issue #241: Wrong datatype in error message

Correct assertion error when CoNLL parser fails and expand error
message.

* Update neuralcoref/train/conllparser.py

* Update neuralcoref/train/conllparser.py

* Update neuralcoref/train/conllparser.py

Co-authored-by: Dave Shepard (CDH) <dave@humnet.ucla.edu>
Co-authored-by: Sofie Van Landeghem <svlandeg@users.noreply.github.com>

Author: 3 people

neuralcoref/train/conllparser.py

@@ -348,11 +348,11 @@ def add_conll_utterance(
         # Convert conll tokens coref index in spacy tokens indexes
         identified_gold = [False] * len(corefs)
         for coref in corefs:
-            assert (
-                coref["label"] is not None
-                and coref["start"] is not None
-                and coref["end"] is not None
-            ), ("Error in coreference " + coref + " in " + parsed)
+            missing_values = [key for key in ['label', 'start', 'end', ] if coref.get(key, None) is None]
+            if missing_values:
+                found_values = {key: coref[key] for key in ['label', 'start', 'end'] if coref.get(key, None) is not None}
+                raise Exception(f"Coref {self.name} with fields {found_values} has empty values for the keys {missing_values}.")
+
             coref["start"] = conll_lookup[coref["start"]][0]
             coref["end"] = conll_lookup[coref["end"]][-1]