If newer versions are using Jedi (e.g. at the moment Python 3.7), it shouldn't just result in a grammar issue, just because that grammar doesn't not exist. Just take the Python 3.6 grammar instead.

jedi/_compatibility.py

@@ -233,6 +233,11 @@ try:
 except ImportError:
     from itertools import izip_longest as zip_longest  # Python 2
 
+try:
+    FileNotFoundError = FileNotFoundError
+except NameError:
+    FileNotFoundError = IOError
+
 
 def no_unicode_pprint(dct):
     """