Exit the generator for Python 3.7 and up

pokedex/db/translations.py

@@ -28,6 +28,7 @@ import csv
 import io
 import os
 import re
+import sys
 from collections import defaultdict
 
 import six
@@ -377,7 +378,13 @@ def group_by_object(stream):
     Yields ((class name, object ID), (list of messages)) pairs.
     """
     stream = iter(stream)
-    current = next(stream)
+    try:
+        current = next(stream)
+    except StopIteration:
+        if sys.version_info >= (3, 7):
+            return
+        else:
+            raise StopIteration
     current_key = current.cls, current.id
     group = [current]
     for message in stream: