mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-26 19:55:24 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 8

bpo-28598: Support __rmod__ for RHS subclasses of str in % string formatting operations (#51)

Browse source 
When you use `'%s' % SubClassOfStr()`, where `SubClassOfStr.__rmod__` exists, the reverse operation is ignored as normally such string formatting operations use the `PyUnicode_Format()` fast path. This patch tests for subclasses of `str` first and picks the slow path in that case.

Patch by Martijn Pieters.
This commit is contained in:
Martijn Pieters 2017-02-23 13:38:04 +00:00 • committed by Serhiy Storchaka
parent 2771304357
commit d7e64337ef
3 changed files with 22 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

12
Python/ceval.c
View file

@ -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);