Add exception handling and logger in metadata provider

cps/metadata_provider/scholar.py

@@ -28,8 +28,12 @@ try:
 except FakeUserAgentError:
     raise ImportError("No module named 'scholarly'")
 
+from cps import logger
 from cps.services.Metadata import MetaRecord, MetaSourceInfo, Metadata
 
+log = logger.create()
+
+
 class scholar(Metadata):
     __name__ = "Google Scholar"
     __id__ = "googlescholar"
@@ -44,7 +48,11 @@ class scholar(Metadata):
             if title_tokens:
                 tokens = [quote(t.encode("utf-8")) for t in title_tokens]
                 query = " ".join(tokens)
-            scholar_gen = itertools.islice(scholarly.search_pubs(query), 10)
+            try:
+                scholar_gen = itertools.islice(scholarly.search_pubs(query), 10)
+            except Exception as e:
+                log.warning(e)
+                return None
             for result in scholar_gen:
                 match = self._parse_search_result(
                     result=result, generic_cover="", locale=locale