diff --git a/jedi/evaluate/finder.py b/jedi/evaluate/finder.py
index 832a7111..822f9ab7 100644
--- a/jedi/evaluate/finder.py
+++ b/jedi/evaluate/finder.py
@@ -402,25 +402,6 @@ def check_flow_information(evaluator, flow, search_name_part, pos):
 
 
 def _check_isinstance_type(evaluator, stmt, search_name):
-    def names(call, use_previous=False):
-        def check(call):
-            while call is not None:
-                if not isinstance(call, pr.Call):  # Could be an Array.
-                    raise ValueError
-                yield unicode(call.name)
-                if use_previous:
-                    call = call.previous
-                else:
-                    call = call.next
-
-        try:
-            if use_previous:
-                return list(check(call))
-            else:
-                return list(reversed(list(check(call))))
-        except ValueError:
-            return []
-
     try:
         expression_list = stmt.expression_list()
         # this might be removed if we analyze and, etc
@@ -437,7 +418,12 @@ def _check_isinstance_type(evaluator, stmt, search_name):
         assert len(classes) == 1
         assert isinstance(obj[0], pr.Call)
 
-        assert names(obj[0]) == names(search_name.parent, search_name)
+        prev = search_name.parent
+        while prev.previous is not None:
+            prev = prev.previous
+        # Do a simple get_code comparison. They should just have the same code,
+        # and everything will be all right.
+        assert obj[0].get_code() == prev.get_code()
         assert isinstance(classes[0], pr.StatementElement)  # can be type or tuple
     except AssertionError:
         return []
diff --git a/jedi/evaluate/sys_path.py b/jedi/evaluate/sys_path.py
index 23622a82..20d42fc4 100644
--- a/jedi/evaluate/sys_path.py
+++ b/jedi/evaluate/sys_path.py
@@ -88,17 +88,14 @@ def _paths_from_insert(module_path, exe):
 
 def _paths_from_call_expression(module_path, call):
     """ extract the path from either "sys.path.append" or "sys.path.insert" """
-    if not call.next_is_execution():
-        return
+    names = call.names()
+    if names[:3] != ['sys', 'path', 'append'] and names[:3] != ['sys', 'path', 'insert']:
+        return []
+    if not call.next.next.next_is_execution():
+        return []
 
-    n = call.name
-    if not isinstance(n, pr.Name) or len(n.names) != 3:
-        return
-    names = [unicode(x) for x in n.names]
-    if names[:2] != ['sys', 'path']:
-        return
     cmd = names[2]
-    exe = call.next
+    exe = call.next.next.next
     path = None
     if cmd == 'insert' and len(exe) == 2:
         path = _paths_from_insert(module_path, exe)
diff --git a/jedi/parser/representation.py b/jedi/parser/representation.py
index bf7b93da..9e6efbc3 100644
--- a/jedi/parser/representation.py
+++ b/jedi/parser/representation.py
@@ -1396,6 +1396,21 @@ class Call(StatementElement):
     def get_code(self):
         return self.name.get_code() + super(Call, self).get_code()
 
+    def names(self):
+        """
+        Generate an array of string names. If a call is not just names,
+        raise an error.
+        """
+        def check(call):
+            while call is not None:
+                if not isinstance(call, Call):  # Could be an Array.
+                    break
+                yield unicode(call.name)
+                call = call.next
+
+        return list(check(self))
+
+
     def __repr__(self):
         return "<%s: %s>" % (type(self).__name__, self.name)