EditorWindow failed when used stand-alone if sys.ps1 not set.
Bug 1010370 Dave Florek

M    EditorWindow.py
M    PyShell.py
M    NEWS.txt
diff --git a/Lib/idlelib/EditorWindow.py b/Lib/idlelib/EditorWindow.py
index 442d718..397d12e 100644
--- a/Lib/idlelib/EditorWindow.py
+++ b/Lib/idlelib/EditorWindow.py
@@ -85,6 +85,10 @@
         self.flist = flist
         root = root or flist.root
         self.root = root
+        try:
+            sys.ps1
+        except AttributeError:
+            sys.ps1 = '>>> '
         self.menubar = Menu(root)
         self.top = top = WindowList.ListedToplevel(root, menu=self.menubar)
         if flist: