diff --git a/Lib/test/test_str.py b/Lib/test/test_str.py
index 5bb9f4867bcb0e..8b306f4e8a4b0c 100644
--- a/Lib/test/test_str.py
+++ b/Lib/test/test_str.py
@@ -465,6 +465,15 @@ def test_startswith_endswith_errors(self):
self.assertIn('str', exc)
self.assertIn('tuple', exc)
+ def test_issue28598_strsubclass_rhs(self):
+ # A subclass of str with an __rmod__ method should be able to hook
+ # into the % operator
+ class SubclassedStr(str):
+ def __rmod__(self, other):
+ return 'Success, self.__rmod__({!r}) was called'.format(other)
+ self.assertEqual('lhs %% %r' % SubclassedStr('rhs'),
+ "Success, self.__rmod__('lhs %% %r') was called")
+
def test_main():
test_support.run_unittest(StrTest)
diff --git a/Misc/NEWS b/Misc/NEWS
index 4523df5a936155..407bf0fffe5220 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@ What's New in Python 2.7.14?
Core and Builtins
-----------------
+- bpo-28598: Support __rmod__ for subclasses of str being called before
+ str.__mod__. Patch by Martijn Pieters.
+
- bpo-29602: Fix incorrect handling of signed zeros in complex constructor for
complex subclasses and for inputs having a __complex__ method. Patch
by Serhiy Storchaka.
diff --git a/Python/ceval.c b/Python/ceval.c
index 2af78ff8747411..733f0776ecfbcc 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1446,10 +1446,14 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
{
w = POP();
v = TOP();
- if (PyString_CheckExact(v))
+ if (PyString_CheckExact(v)
+ && (!PyString_Check(w) || PyString_CheckExact(w))) {
+ /* fast path; string formatting, but not if the RHS is a str subclass
+ (see issue28598) */
x = PyString_Format(v, w);
- else
+ } else {
x = PyNumber_Remainder(v, w);
+ }
Py_DECREF(v);
Py_DECREF(w);
SET_TOP(x);
pFad - Phonifier reborn
Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.
Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.
Alternative Proxies:
Alternative Proxy
pFad Proxy
pFad v3 Proxy
pFad v4 Proxy