commit da2c7ebd234fc904f6d6de2191eb5f72e8992c95
author Benjamin Peterson <benjamin@python.org> Sat Mar 23 22:32:00 2013 -0500
committer Benjamin Peterson <benjamin@python.org> Sat Mar 23 22:32:00 2013 -0500
tree fe5ea090417c5bb6a82e9ea3a7d1421b5227127b
parent 7e2f197a2bc3d15ff8c504154f48a3c2435c992f

allow any type with __getitem__ to be a mapping for the purposes of % (#15801)

Objects/stringobject.c

diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 7871323..1209197 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -4257,8 +4257,8 @@
         arglen = -1;
         argidx = -2;
     }
-    if (PyMapping_Check(args) && !PyTuple_Check(args) &&
-        !PyObject_TypeCheck(args, &PyBaseString_Type))
+    if (Py_TYPE(args)->tp_as_mapping && Py_TYPE(args)->tp_as_mapping->mp_subscript &&
+        !PyTuple_Check(args) && !PyObject_TypeCheck(args, &PyBaseString_Type))
         dict = args;
     while (--fmtcnt >= 0) {
         if (*fmt != '%') {

Objects/unicodeobject.c

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 981a98b..0ead06f 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -8287,8 +8287,8 @@
         arglen = -1;
         argidx = -2;
     }
-    if (PyMapping_Check(args) && !PyTuple_Check(args) &&
-        !PyObject_TypeCheck(args, &PyBaseString_Type))
+    if (Py_TYPE(args)->tp_as_mapping && Py_TYPE(args)->tp_as_mapping->mp_subscript &&
+        !PyTuple_Check(args) && !PyObject_TypeCheck(args, &PyBaseString_Type))
         dict = args;
 
     while (--fmtcnt >= 0) {