Index: Lib/os.py
===================================================================
--- Lib/os.py	(revision 76625)
+++ Lib/os.py	(working copy)
@@ -650,6 +650,10 @@
             return returncode
         else:
             return returncode << 8  # Shift left to match old behavior
+    def __enter__(self):
+        return self
+    def __exit__(self, *args):
+        self.close()
     def __getattr__(self, name):
         return getattr(self._stream, name)
     def __iter__(self):
Index: Lib/test/test_popen.py
===================================================================
--- Lib/test/test_popen.py	(revision 76625)
+++ Lib/test/test_popen.py	(working copy)
@@ -49,6 +49,10 @@
         else:
             self.assertEqual(os.popen("exit 42").close(), 42 << 8)
 
+    def test_contextmanager(self):
+        with os.popen("echo hello") as f:
+            self.assertEqual(f.read(), "hello\n")
+
 def test_main():
     support.run_unittest(PopenTest)