Get rid of xreadlines() (methods).
diff --git a/Doc/tools/undoc_symbols.py b/Doc/tools/undoc_symbols.py
index 3d776fa..782ab6c 100644
--- a/Doc/tools/undoc_symbols.py
+++ b/Doc/tools/undoc_symbols.py
@@ -50,7 +50,7 @@
 
 def findnames(file, prefixes=()):
     names = {}
-    for line in file.xreadlines():
+    for line in file:
         if line[0] == '!':
             continue
         fields = line.split()