Switch grammars depending on Python version.

jedi/api/__init__.py

@@ -104,7 +104,7 @@ class Script(object):
 
         cache.clear_time_caches()
         debug.reset_time()
-        self._grammar = load_grammar('grammar3.4')
+        self._grammar = load_grammar('grammar%s.%s' % sys.version_info[:2])
         self._user_context = UserContext(self.source, self._pos)
         self._parser = UserContextParser(self._grammar, self.source, path,
                                          self._pos, self._user_context)

jedi/parser/__init__.py

@@ -33,6 +33,13 @@ _loaded_grammars = {}
 
 
 def load_grammar(file='grammar3.4'):
+    # For now we only support two different Python syntax versions: The latest
+    # Python 3 and Python 2. This may change.
+    if file.startswith('grammar3'):
+        file = 'grammar3.4'
+    else:
+        file = 'grammar2.7'
+
     global _loaded_grammars
     path = os.path.join(os.path.dirname(__file__), file) + '.txt'
     try: