Enable ruff flake8-simplify rule

notes-to-self/file-read-latency.py

@@ -8,23 +8,22 @@
 # ns per call, instead of ~500 ns/call for the syscall and related overhead.
 # That's probably more fair -- the BufferedIOBase code can't service random
 # accesses, even if your working set fits entirely in RAM.
-f = open("/etc/passwd", "rb")  # , buffering=0)
+with open("/etc/passwd", "rb") as f:  # , buffering=0)
+    while True:
+        start = time.perf_counter()
+        for _ in range(COUNT):
+            f.seek(0)
+            f.read(1)
+        between = time.perf_counter()
+        for _ in range(COUNT):
+            f.seek(0)
+        end = time.perf_counter()
 
-while True:
-    start = time.perf_counter()
-    for _ in range(COUNT):
-        f.seek(0)
-        f.read(1)
-    between = time.perf_counter()
-    for _ in range(COUNT):
-        f.seek(0)
-    end = time.perf_counter()
-
-    both = (between - start) / COUNT * 1e9
-    seek = (end - between) / COUNT * 1e9
-    read = both - seek
-    print(
-        "{:.2f} ns/(seek+read), {:.2f} ns/seek, estimate ~{:.2f} ns/read".format(
-            both, seek, read
+        both = (between - start) / COUNT * 1e9
+        seek = (end - between) / COUNT * 1e9
+        read = both - seek
+        print(
+            "{:.2f} ns/(seek+read), {:.2f} ns/seek, estimate ~{:.2f} ns/read".format(
+                both, seek, read
+            )
         )
-    )

notes-to-self/proxy-benchmarks.py

@@ -156,24 +156,24 @@ def check(cls):
 for cls in classes:
     check(cls)
 
-f = open("/etc/passwd")
-objs = [c(f) for c in classes]
-
-COUNT = 1000000
-try:
-    import __pypy__  # noqa: F401  # __pypy__ imported but unused
-except ImportError:
-    pass
-else:
-    COUNT *= 10
-
-while True:
-    print("-------")
-    for obj in objs:
-        start = time.perf_counter()
-        for _ in range(COUNT):
-            obj.fileno()
-            # obj.fileno
-        end = time.perf_counter()
-        per_usec = COUNT / (end - start) / 1e6
-        print("{:7.2f} / us: {} ({})".format(per_usec, obj.strategy, obj.works_for))
+with open("/etc/passwd") as f:
+    objs = [c(f) for c in classes]
+
+    COUNT = 1000000
+    try:
+        import __pypy__  # noqa: F401  # __pypy__ imported but unused
+    except ImportError:
+        pass
+    else:
+        COUNT *= 10
+
+    while True:
+        print("-------")
+        for obj in objs:
+            start = time.perf_counter()
+            for _ in range(COUNT):
+                obj.fileno()
+                # obj.fileno
+            end = time.perf_counter()
+            per_usec = COUNT / (end - start) / 1e6
+            print("{:7.2f} / us: {} ({})".format(per_usec, obj.strategy, obj.works_for))

notes-to-self/trace.py

@@ -149,5 +149,6 @@ async def parent():
     print("parent: all done!")
 
 
-t = Trace(open("/tmp/t.json", "w"))
-trio.run(parent, instruments=[t])
+with open("/tmp/t.json", "w") as t_json:
+    t = Trace(t_json)
+    trio.run(parent, instruments=[t])

notes-to-self/win-waitable-timer.py

@@ -24,13 +24,14 @@
 # make this fairly straightforward, but you obviously need to use a separate
 # time source
 
+import contextlib
 from datetime import datetime, timedelta, timezone
 
 import cffi
 import trio
 from trio._core._windows_cffi import ffi, kernel32, raise_winerror
 
-try:
+with contextlib.suppress(cffi.CDefError):
     ffi.cdef(
         """
 typedef struct _PROCESS_LEAP_SECOND_INFO {
@@ -50,8 +51,6 @@
 } SYSTEMTIME, *PSYSTEMTIME, *LPSYSTEMTIME;
 """
     )
-except cffi.CDefError:
-    pass
 
 ffi.cdef(
     """

pyproject.toml

@@ -30,12 +30,14 @@ select = [
   "B",  # flake8-bugbear
   "YTT",  # flake8-2020
   "ASYNC",  # flake8-async
+  "SIM",  # flake8-simplify
 ]
 extend-ignore = [
     'F403',  # undefined-local-with-import-star
     'F405',  # undefined-local-with-import-star-usage
     'E402',  # module-import-not-at-top-of-file (usually OS-specific)
     'E501',  # line-too-long
+    'SIM117',  # multiple-with-statements (messes up lots of context-based stuff and looks bad)
 ]
 
 include = ["*.py", "*.pyi", "**/pyproject.toml"]

setup.py

@@ -2,7 +2,8 @@
 
 __version__ = "0.0.0"  # Overwritten from _version.py below, needed for linter to identify that this variable is defined.
 
-exec(open("trio/_version.py", encoding="utf-8").read())
+with open("trio/_version.py", encoding="utf-8") as version_code:
+    exec(version_code.read())
 
 LONG_DESC = """\
 .. image:: https://raw.githubusercontent.com/python-trio/trio/9b0bec646a31e0d0f67b8b6ecc6939726faf3e17/logo/logo-with-background.svg

trio/_core/_io_epoll.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import contextlib
 import select
 import sys
 from collections import defaultdict
@@ -324,7 +325,5 @@ def notify_closing(self, fd: int | _HasFileNo) -> None:
             _core.ClosedResourceError("another task closed this fd"),
         )
         del self._registered[fd]
-        try:
+        with contextlib.suppress(OSError, ValueError):
             self._epoll.unregister(fd)
-        except (OSError, ValueError):
-            pass

trio/_core/_multierror.py

@@ -328,7 +328,7 @@ def catch(
         return MultiErrorCatcher(handler)
 
 
-if TYPE_CHECKING:
+if TYPE_CHECKING:  # noqa: SIM108
     _ExceptionGroup = ExceptionGroup[Exception]
 else:
     _ExceptionGroup = ExceptionGroup
@@ -432,12 +432,15 @@ def controller(operation: tputil.ProxyOperation) -> Any | None:
             # 'opname' that isn't __getattr__ or __getattribute__. So there's
             # no missing test we could add, and no value in coverage nagging
             # us about adding one.
-            if operation.opname in [
-                "__getattribute__",
-                "__getattr__",
-            ]:  # pragma: no cover
-                if operation.args[0] == "tb_next":
-                    return tb_next
+            if (
+                operation.opname
+                in {
+                    "__getattribute__",
+                    "__getattr__",
+                }
+                and operation.args[0] == "tb_next"
+            ):  # pragma: no cover
+                return tb_next
             return operation.delegate()  # Deligate is reverting to original behaviour
 
         return cast(

trio/_core/_run.py

@@ -18,7 +18,7 @@
     Iterator,
     Sequence,
 )
-from contextlib import AbstractAsyncContextManager, contextmanager
+from contextlib import AbstractAsyncContextManager, contextmanager, suppress
 from contextvars import copy_context
 from heapq import heapify, heappop, heappush
 from math import inf
@@ -792,7 +792,9 @@ def cancel_called(self) -> bool:
         cancelled, then :attr:`cancelled_caught` is usually more
         appropriate.
         """
-        if self._cancel_status is not None or not self._has_been_entered:
+        if (  # noqa: SIM102  # collapsible-if but this way is nicer
+            self._cancel_status is not None or not self._has_been_entered
+        ):
             # Scope is active or not yet entered: make sure cancel_called
             # is true if the deadline has passed. This shouldn't
             # be able to actually change behavior, since we check for
@@ -1708,10 +1710,7 @@ def spawn_impl(
         # Propagate contextvars
         ######
         if context is None:
-            if system_task:
-                context = self.system_context.copy()
-            else:
-                context = copy_context()
+            context = self.system_context.copy() if system_task else copy_context()
 
         ######
         # Call the function and get the coroutine object, while giving helpful
@@ -1943,10 +1942,8 @@ def current_trio_token(self) -> TrioToken:
     # This gets called from signal context
     def deliver_ki(self) -> None:
         self.ki_pending = True
-        try:
+        with suppress(RunFinishedError):
             self.entry_queue.run_sync_soon(self._deliver_ki_cb)
-        except RunFinishedError:
-            pass
 
     def _deliver_ki_cb(self) -> None:
         if not self.ki_pending:

trio/_core/_tests/test_asyncgen.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import contextlib
 import sys
 import weakref
 from collections.abc import AsyncGenerator
@@ -17,10 +18,8 @@ def test_asyncgen_basics() -> None:
 
     async def example(cause: str) -> AsyncGenerator[int, None]:
         try:
-            try:
+            with contextlib.suppress(GeneratorExit):
                 yield 42
-            except GeneratorExit:
-                pass
             await _core.checkpoint()
         except _core.Cancelled:
             assert "exhausted" not in cause
@@ -44,14 +43,14 @@ async def async_main() -> None:
         with pytest.warns(
             ResourceWarning, match="Async generator.*collected before.*exhausted"
         ):
-            assert 42 == await example("abandoned").asend(None)
+            assert await example("abandoned").asend(None) == 42
             gc_collect_harder()
         await _core.wait_all_tasks_blocked()
         assert collected.pop() == "abandoned"
 
         aiter = example("exhausted 1")
         try:
-            assert 42 == await aiter.asend(None)
+            assert await aiter.asend(None) == 42
         finally:
             await aiter.aclose()
         assert collected.pop() == "exhausted 1"
@@ -67,7 +66,7 @@ async def async_main() -> None:
         aiter = example("exhausted 3")
         try:
             saved.append(aiter)
-            assert 42 == await aiter.asend(None)
+            assert await aiter.asend(None) == 42
         finally:
             await aiter.aclose()
         assert collected.pop() == "exhausted 3"
@@ -83,7 +82,7 @@ async def async_main() -> None:
             collected.append("outlived run")
         else:
             saved.append(example("outlived run"))
-            assert 42 == await saved[-1].asend(None)
+            assert await saved[-1].asend(None) == 42
             assert collected == []
 
     _core.run(async_main)
@@ -137,8 +136,8 @@ async def funky_agen() -> AsyncGenerator[int, None]:
     async def async_main() -> None:
         aiter = funky_agen()
         saved.append(aiter)
-        assert 1 == await aiter.asend(None)
-        assert 2 == await aiter.asend(None)
+        assert await aiter.asend(None) == 1
+        assert await aiter.asend(None) == 2
 
     _core.run(async_main)
     assert record == ["cleanup 2", "cleanup 1"]
@@ -178,7 +177,7 @@ async def async_main() -> None:
         for idx in range(100):
             ag_chain = agen(idx, ag_chain)
         saved.append(ag_chain)
-        assert 1 == await ag_chain.asend(None)
+        assert await ag_chain.asend(None) == 1
         assert record == []
 
     _core.run(async_main)
@@ -320,7 +319,7 @@ async def example(arg: str) -> AsyncGenerator[int, None]:
 
     async def async_main() -> None:
         await step_outside_async_context(example("theirs"))
-        assert 42 == await example("ours").asend(None)
+        assert await example("ours").asend(None) == 42
         gc_collect_harder()
         assert record == ["firstiter theirs", "finalizer theirs"]
         record[:] = []

trio/_core/_tests/test_guest_mode.py

@@ -1,4 +1,5 @@
 import asyncio
+import contextlib
 import contextvars
 import queue
 import signal
@@ -596,10 +597,8 @@ async def agen(label):
             yield 1
         finally:
             library = sniffio.current_async_library()
-            try:
+            with contextlib.suppress(trio.Cancelled):
                 await sys.modules[library].sleep(0)
-            except trio.Cancelled:
-                pass
             record.add((label, library))
 
     async def iterate_in_aio():

trio/_core/_tests/test_multierror.py

@@ -440,10 +440,9 @@ def run_script(name: str) -> subprocess.CompletedProcess[bytes]:
 
     env = dict(os.environ)
     print("parent PYTHONPATH:", env.get("PYTHONPATH"))
+    pp = []
     if "PYTHONPATH" in env:  # pragma: no cover
         pp = env["PYTHONPATH"].split(os.pathsep)
-    else:
-        pp = []
     pp.insert(0, str(trio_path))
     pp.insert(0, str(script_path.parent))
     env["PYTHONPATH"] = os.pathsep.join(pp)

trio/_core/_tests/test_run.py

@@ -15,7 +15,7 @@
     Callable,
     Generator,
 )
-from contextlib import ExitStack, contextmanager
+from contextlib import ExitStack, contextmanager, suppress
 from math import inf
 from typing import Any, NoReturn, TypeVar, cast
 
@@ -311,10 +311,8 @@ async def test_current_statistics(mock_clock: _core.MockClock) -> None:
 
     # A child that sticks around to make some interesting stats:
     async def child() -> None:
-        try:
+        with suppress(_core.Cancelled):
             await sleep_forever()
-        except _core.Cancelled:
-            pass
 
     stats = _core.current_statistics()
     print(stats)
@@ -1089,10 +1087,8 @@ async def child() -> None:
         try:
             raise KeyError
         except Exception:
-            try:
+            with suppress(Exception):
                 await sleep_forever()
-            except Exception:
-                pass
             raise
 
     with pytest.raises(KeyError):
@@ -1215,10 +1211,8 @@ def test_TrioToken_run_sync_soon_idempotent_requeue() -> None:
 
     def redo(token: _core.TrioToken) -> None:
         record.append(None)
-        try:
+        with suppress(_core.RunFinishedError):
             token.run_sync_soon(redo, token, idempotent=True)
-        except _core.RunFinishedError:
-            pass
 
     async def main() -> None:
         token = _core.current_trio_token()