[mypyc] Implement bytes.endswith#20447
Merged
JukkaL merged 3 commits intopython:masterfrom Jan 15, 2026
Merged
Conversation
JukkaL
reviewed
Jan 5, 2026
mypyc/lib-rt/bytes_ops.c
Outdated
|
|
||
| return memcmp(self_buf + (self_len - subobj_len), subobj_buf, (size_t)subobj_len) == 0 ? 1 : 0; | ||
| } | ||
| _Py_IDENTIFIER(endswith); |
esarp
force-pushed
the
mypycBytesEndswith
branch
from
d74ed5a to
c4f5081
Compare
esarp
force-pushed
the
mypycBytesEndswith
branch
from
4c55a57 to
22a2e04
Compare
JukkaL
approved these changes
Jan 15, 2026
michaelm-openai
pushed a commit
to michaelm-openai/mypy
that referenced
this pull request
Jan 16, 2026
Rounding out python#20387 and implementing `bytes.endswith`. Simple benchmark shows a ~6.4x improvement. Tested with the following benchmark code: ``` import time def bench(suffix: bytes, a: list[bytes], n: int) -> int: i = 0 for x in range(n): for b in a: if b.endswith(suffix): i += 1 return i a = [b"foo", b"barasdfsf", b"foobar", b"ab", b"asrtert", b"sertyeryt"] n = 5 * 1000 * 1000 suffix = b"foo" bench(suffix, a, n) t0 = time.time() bench(suffix, a, n) td = time.time() - t0 print(f"{td}s") ``` Output: ``` $ python bench.py 0.9002199172973633s $ python -c "import bench" 0.13828086853027344s ```
michaelm-openai
pushed a commit
to michaelm-openai/mypy
that referenced
this pull request
Jan 16, 2026
Rounding out python#20387 and implementing `bytes.endswith`. Simple benchmark shows a ~6.4x improvement. Tested with the following benchmark code: ``` import time def bench(suffix: bytes, a: list[bytes], n: int) -> int: i = 0 for x in range(n): for b in a: if b.endswith(suffix): i += 1 return i a = [b"foo", b"barasdfsf", b"foobar", b"ab", b"asrtert", b"sertyeryt"] n = 5 * 1000 * 1000 suffix = b"foo" bench(suffix, a, n) t0 = time.time() bench(suffix, a, n) td = time.time() - t0 print(f"{td}s") ``` Output: ``` $ python bench.py 0.9002199172973633s $ python -c "import bench" 0.13828086853027344s ```
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Rounding out #20387 and implementing
bytes.endswith. Simple benchmark shows a ~6.4x improvement.Tested with the following benchmark code:
Output: