Added tag_prevrange analogous to rag_nextrange.
diff --git a/Lib/lib-tk/Tkinter.py b/Lib/lib-tk/Tkinter.py
index e59c3d5..61cb07e 100644
--- a/Lib/lib-tk/Tkinter.py
+++ b/Lib/lib-tk/Tkinter.py
@@ -1616,6 +1616,9 @@
 	def tag_nextrange(self, tagName, index1, index2=None):
 		return self.tk.splitlist(self.tk.call(
 			self._w, 'tag', 'nextrange', tagName, index1, index2))
+	def tag_prevrange(self, tagName, index1, index2=None):
+		return self.tk.splitlist(self.tk.call(
+			self._w, 'tag', 'prevrange', tagName, index1, index2))
 	def tag_raise(self, tagName, aboveThis=None):
 		self.tk.call(
 			self._w, 'tag', 'raise', tagName, aboveThis)