diff -r a892a0dd8190 Python/bltinmodule.c
--- a/Python/bltinmodule.c	Tue Mar 22 15:57:03 2011 -0700
+++ b/Python/bltinmodule.c	Wed Mar 23 00:23:46 2011 +0100
@@ -1520,12 +1520,39 @@
             return NULL;
     }
 
-    if (end == NULL)
+    if (end == NULL) {
         err = PyFile_WriteString("\n", file);
-    else
+        if (err)
+            return NULL;
+    }
+    else {
+	PyObject *result = NULL;
         err = PyFile_WriteObject(end, file, Py_PRINT_RAW);
-    if (err)
-        return NULL;
+        if (err)
+            return NULL;
+
+	/* if file is a terminal, flush it now */
+	result = PyObject_CallMethod(file, "isatty", NULL);
+	if (result != NULL) {
+	    int rc = PyObject_IsTrue(result);
+	    Py_DECREF(result);
+	    if (rc < 0)
+		return NULL;
+
+	    if (rc) {
+		result = PyObject_CallMethod(file, "flush", NULL);
+
+		if (result != NULL)
+		    Py_DECREF(result);
+		else
+		    return NULL;
+	    }
+	}
+	else {
+	    /* no isatty() method, ignore it */
+	    PyErr_Clear();
+	}
+    }
 
     Py_RETURN_NONE;
 }