diff options
| -rw-r--r-- | Lib/test/test_unicode.py | 9 | ||||
| -rw-r--r-- | Misc/NEWS | 4 | ||||
| -rw-r--r-- | Python/ceval.c | 12 |
3 files changed, 22 insertions, 3 deletions
diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py index b1f7c89..f70504c 100644 --- a/Lib/test/test_unicode.py +++ b/Lib/test/test_unicode.py @@ -1448,6 +1448,15 @@ class UnicodeTest(string_tests.CommonTest, with self.assertRaises(ValueError): result = format_string % 2.34 + 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") + @support.cpython_only def test_formatting_huge_precision_c_limits(self): from _testcapi import INT_MAX @@ -10,6 +10,9 @@ What's New in Python 3.7.0 alpha 1? Core and Builtins ----------------- +- bpo-28598: Support __rmod__ for subclasses of str being called before + str.__mod__. Patch by Martijn Pieters. + - bpo-29607: Fix stack_effect computation for CALL_FUNCTION_EX. Patch by Matthieu Dartiailh. @@ -19,6 +22,7 @@ Core and Builtins - bpo-29347: Fixed possibly dereferencing undefined pointers when creating weakref objects. + - bpo-29463: Add ``docstring`` field to Module, ClassDef, FunctionDef, and AsyncFunctionDef ast nodes. docstring is not first stmt in their body anymore. It affects ``co_firstlineno`` and ``co_lnotab`` of code object diff --git a/Python/ceval.c b/Python/ceval.c index 81c89df..0a82965 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -1354,9 +1354,15 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag) TARGET(BINARY_MODULO) { PyObject *divisor = POP(); PyObject *dividend = TOP(); - PyObject *res = PyUnicode_CheckExact(dividend) ? - PyUnicode_Format(dividend, divisor) : - PyNumber_Remainder(dividend, divisor); + PyObject *res; + if (PyUnicode_CheckExact(dividend) && ( + !PyUnicode_Check(divisor) || PyUnicode_CheckExact(divisor))) { + // fast path; string formatting, but not if the RHS is a str subclass + // (see issue28598) + res = PyUnicode_Format(dividend, divisor); + } else { + res = PyNumber_Remainder(dividend, divisor); + } Py_DECREF(divisor); Py_DECREF(dividend); SET_TOP(res); |