Mark xreadlines deprecated. Don't use f.xreadlines() in test_iter.py.

Lib/test/test_iter.py

@@ -269,7 +269,7 @@ class TestCase(unittest.TestCase):
         try:
             self.assertEqual(list(f), ["0\n", "1\n", "2\n", "3\n", "4\n"])
             f.seek(0, 0)
-            self.assertEqual(list(f.xreadlines()),
+            self.assertEqual(list(f),
                              ["0\n", "1\n", "2\n", "3\n", "4\n"])
         finally:
             f.close()
@@ -302,7 +302,7 @@ class TestCase(unittest.TestCase):
         try:
             self.assertEqual(tuple(f), ("0\n", "1\n", "2\n", "3\n", "4\n"))
             f.seek(0, 0)
-            self.assertEqual(tuple(f.xreadlines()),
+            self.assertEqual(tuple(f),
                              ("0\n", "1\n", "2\n", "3\n", "4\n"))
         finally:
             f.close()

Lib/test/test_xreadline.py

 from test.test_support import verbose
 
+import warnings
+warnings.filterwarnings('ignore', "xreadlines", DeprecationWarning)
+
 class XReader:
     def __init__(self):
         self.count = 5

Modules/xreadlinesmodule.c

@@ -173,4 +173,6 @@ initxreadlines(void)
 {
 	XReadlinesObject_Type.ob_type = &PyType_Type;
 	Py_InitModule("xreadlines", xreadlines_functions);
+	PyErr_Warn(PyExc_DeprecationWarning,
+		   "xreadlines is deprecated; use 'for line in file'.");
 }