From 7c8233180c3caa7d89854cda441f3c08d154366b Mon Sep 17 00:00:00 2001 From: Ruiyang Ke Date: Mon, 2 Feb 2026 02:04:18 -0800 Subject: [PATCH] gh-144380: Fix incorrect type check in `buffered_iternext()` (GH-144381) (cherry picked from commit 40d07cad38bf3ce60f4ca03f1836e8650fe40df5) Co-authored-by: Ruiyang Ke --- .../Library/2026-02-01-15-25-00.gh-issue-144380.U7py_s.rst | 1 + Modules/_io/bufferedio.c | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2026-02-01-15-25-00.gh-issue-144380.U7py_s.rst diff --git a/Misc/NEWS.d/next/Library/2026-02-01-15-25-00.gh-issue-144380.U7py_s.rst b/Misc/NEWS.d/next/Library/2026-02-01-15-25-00.gh-issue-144380.U7py_s.rst new file mode 100644 index 00000000000000..4b5b1b3776d735 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-02-01-15-25-00.gh-issue-144380.U7py_s.rst @@ -0,0 +1 @@ +Improve performance of :class:`io.BufferedReader` line iteration by ~49%. diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c index 65d69d0d5e13d0..2e8566168de4ba 100644 --- a/Modules/_io/bufferedio.c +++ b/Modules/_io/bufferedio.c @@ -1486,8 +1486,8 @@ buffered_iternext(buffered *self) _PyIO_State *state = find_io_state_by_def(Py_TYPE(self)); tp = Py_TYPE(self); - if (Py_IS_TYPE(tp, state->PyBufferedReader_Type) || - Py_IS_TYPE(tp, state->PyBufferedRandom_Type)) + if (tp == state->PyBufferedReader_Type || + tp == state->PyBufferedRandom_Type) { /* Skip method call overhead for speed */ line = _buffered_readline(self, -1);