diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000000..f57321189e
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,39 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.4.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-toml
+      - id: check-merge-conflict
+      - id: mixed-line-ending
+      - id: check-case-conflict
+  - repo: https://github.com/psf/black
+    rev: 23.7.0
+    hooks:
+      - id: black
+  - repo: https://github.com/pycqa/isort
+    rev: 5.12.0
+    hooks:
+      - id: isort
+  - repo: https://github.com/pycqa/flake8
+    rev: 6.1.0
+    hooks:
+      - id: flake8
+        additional_dependencies:
+          - "flake8-pyproject==1.2.3"
+        types: [file]
+        types_or: [python, pyi]
+  - repo: https://github.com/codespell-project/codespell
+    rev: v2.2.5
+    hooks:
+      - id: codespell
+
+ci:
+  autofix_commit_msg: "[pre-commit.ci] auto fixes from pre-commit.com hooks"
+  autofix_prs: true
+  autoupdate_commit_msg: "[pre-commit.ci] pre-commit autoupdate"
+  autoupdate_schedule: weekly
+  skip: [black,isort]
+  submodules: false
diff --git a/docs/Makefile b/docs/Makefile
index 4fd0bb58f2..69095d6d90 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -17,4 +17,4 @@ help:
 # Catch-all target: route all unknown targets to Sphinx using the new
 # "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
 %: Makefile
-	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
\ No newline at end of file
+	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
diff --git a/docs/source/local_customization.py b/docs/source/local_customization.py
index a970ad6e22..f071b6dfbb 100644
--- a/docs/source/local_customization.py
+++ b/docs/source/local_customization.py
@@ -1,11 +1,11 @@
-from docutils.parsers.rst import directives
+from docutils.parsers.rst import directives as directives  # noqa: F401
 from sphinx import addnodes
 from sphinx.domains.python import PyClasslike
-from sphinx.ext.autodoc import (
-    FunctionDocumenter,
-    MethodDocumenter,
-    ClassLevelDocumenter,
-    Options,
+from sphinx.ext.autodoc import (  # noqa: F401
+    ClassLevelDocumenter as ClassLevelDocumenter,
+    FunctionDocumenter as FunctionDocumenter,
+    MethodDocumenter as MethodDocumenter,
+    Options as Options,
 )
 
 """
diff --git a/notes-to-self/afd-lab.py b/notes-to-self/afd-lab.py
index ed420dbdbd..600975482c 100644
--- a/notes-to-self/afd-lab.py
+++ b/notes-to-self/afd-lab.py
@@ -77,22 +77,27 @@
 # matter, energy, and life which lie close at hand yet can never be detected
 # with the senses we have."
 
-import sys
 import os.path
+import sys
+
 sys.path.insert(0, os.path.abspath(os.path.dirname(__file__) + r"\.."))
 
 import trio
+
 print(trio.__file__)
-import trio.testing
 import socket
 
+import trio.testing
+from trio._core._io_windows import _afd_helper_handle, _check, _get_base_socket
 from trio._core._windows_cffi import (
-    ffi, kernel32, AFDPollFlags, IoControlCodes, ErrorCodes
-)
-from trio._core._io_windows import (
-    _get_base_socket, _afd_helper_handle, _check
+    AFDPollFlags,
+    ErrorCodes,
+    IoControlCodes,
+    ffi,
+    kernel32,
 )
 
+
 class AFDLab:
     def __init__(self):
         self._afd = _afd_helper_handle()
@@ -173,4 +178,5 @@ async def main():
             await trio.sleep(2)
             nursery.cancel_scope.cancel()
 
+
 trio.run(main)
diff --git a/notes-to-self/aio-guest-test.py b/notes-to-self/aio-guest-test.py
index b64a11bd04..17d4bfb9e0 100644
--- a/notes-to-self/aio-guest-test.py
+++ b/notes-to-self/aio-guest-test.py
@@ -1,10 +1,13 @@
 import asyncio
+
 import trio
 
+
 async def aio_main():
     loop = asyncio.get_running_loop()
 
     trio_done_fut = loop.create_future()
+
     def trio_done_callback(main_outcome):
         print(f"trio_main finished: {main_outcome!r}")
         trio_done_fut.set_result(main_outcome)
@@ -35,6 +38,7 @@ async def trio_main():
         if n >= 10:
             return
 
+
 async def aio_pingpong(from_trio, to_trio):
     print("aio_pingpong!")
 
diff --git a/notes-to-self/atomic-local.py b/notes-to-self/atomic-local.py
index 212c9eef00..429211eaf6 100644
--- a/notes-to-self/atomic-local.py
+++ b/notes-to-self/atomic-local.py
@@ -3,9 +3,11 @@
 # Has to be a string :-(
 sentinel = "_unique_name"
 
+
 def f():
     print(locals())
 
+
 # code(argcount, kwonlyargcount, nlocals, stacksize, flags, codestring,
 #       constants, names, varnames, filename, name, firstlineno,
 #       lnotab[, freevars[, cellvars]])
diff --git a/notes-to-self/blocking-read-hack.py b/notes-to-self/blocking-read-hack.py
index b301058e85..f4a73f876d 100644
--- a/notes-to-self/blocking-read-hack.py
+++ b/notes-to-self/blocking-read-hack.py
@@ -1,13 +1,16 @@
-import trio
+import errno
 import os
 import socket
-import errno
+
+import trio
 
 bad_socket = socket.socket()
 
+
 class BlockingReadTimeoutError(Exception):
     pass
 
+
 async def blocking_read_with_timeout(fd, count, timeout):
     print("reading from fd", fd)
     cancel_requested = False
@@ -42,4 +45,5 @@ async def kill_it_after_timeout(new_fd):
     finally:
         os.close(new_fd)
 
+
 trio.run(blocking_read_with_timeout, 0, 10, 2)
diff --git a/notes-to-self/estimate-task-size.py b/notes-to-self/estimate-task-size.py
index 1e8597ba42..0010c7a2b4 100644
--- a/notes-to-self/estimate-task-size.py
+++ b/notes-to-self/estimate-task-size.py
@@ -1,15 +1,18 @@
 # Little script to get a rough estimate of how much memory each task takes
 
 import resource
+
 import trio
 import trio.testing
 
 LOW = 1000
 HIGH = 10000
 
+
 async def tinytask():
     await trio.sleep_forever()
 
+
 async def measure(count):
     async with trio.open_nursery() as nursery:
         for _ in range(count):
@@ -23,8 +26,8 @@ async def main():
     low_usage = await measure(LOW)
     high_usage = await measure(HIGH + LOW)
 
-    print("Memory usage per task:",
-          (high_usage.ru_maxrss - low_usage.ru_maxrss) / HIGH)
+    print("Memory usage per task:", (high_usage.ru_maxrss - low_usage.ru_maxrss) / HIGH)
     print("(kilobytes on Linux, bytes on macOS)")
 
+
 trio.run(main)
diff --git a/notes-to-self/fbsd-pipe-close-notify.py b/notes-to-self/fbsd-pipe-close-notify.py
index 7b18f65d6f..ab17f94c3f 100644
--- a/notes-to-self/fbsd-pipe-close-notify.py
+++ b/notes-to-self/fbsd-pipe-close-notify.py
@@ -4,9 +4,8 @@
 #
 # Upstream bug: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=246350
 
-import select
 import os
-import threading
+import select
 
 r, w = os.pipe()
 
diff --git a/notes-to-self/file-read-latency.py b/notes-to-self/file-read-latency.py
index 9af1b7222d..132e29dc4f 100644
--- a/notes-to-self/file-read-latency.py
+++ b/notes-to-self/file-read-latency.py
@@ -8,7 +8,7 @@
 # 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)
+f = open("/etc/passwd", "rb")  # , buffering=0)
 
 while True:
     start = time.perf_counter()
@@ -23,5 +23,8 @@
     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))
+    print(
+        "{:.2f} ns/(seek+read), {:.2f} ns/seek, estimate ~{:.2f} ns/read".format(
+            both, seek, read
+        )
+    )
diff --git a/notes-to-self/graceful-shutdown-idea.py b/notes-to-self/graceful-shutdown-idea.py
index 792344de02..b454d7610a 100644
--- a/notes-to-self/graceful-shutdown-idea.py
+++ b/notes-to-self/graceful-shutdown-idea.py
@@ -1,5 +1,6 @@
 import trio
 
+
 class GracefulShutdownManager:
     def __init__(self):
         self._shutting_down = False
@@ -21,6 +22,7 @@ def cancel_on_graceful_shutdown(self):
     def shutting_down(self):
         return self._shutting_down
 
+
 # Code can check gsm.shutting_down occasionally at appropriate points to see
 # if it should exit.
 #
@@ -31,9 +33,11 @@ async def stream_handler(stream):
     while True:
         with gsm.cancel_on_graceful_shutdown():
             data = await stream.receive_some()
+            print(f"{data = }")
         if gsm.shutting_down:
             break
 
+
 # To trigger the shutdown:
 async def listen_for_shutdown_signals():
     with trio.open_signal_receiver(signal.SIGINT, signal.SIGTERM) as signal_aiter:
diff --git a/notes-to-self/how-does-windows-so-reuseaddr-work.py b/notes-to-self/how-does-windows-so-reuseaddr-work.py
index d8d60d1d66..3189d4d594 100644
--- a/notes-to-self/how-does-windows-so-reuseaddr-work.py
+++ b/notes-to-self/how-does-windows-so-reuseaddr-work.py
@@ -4,8 +4,8 @@
 #
 # See https://github.com/python-trio/trio/issues/928 for details and context
 
-import socket
 import errno
+import socket
 
 modes = ["default", "SO_REUSEADDR", "SO_EXCLUSIVEADDRUSE"]
 bind_types = ["wildcard", "specific"]
diff --git a/notes-to-self/loopy.py b/notes-to-self/loopy.py
index 9f893590bd..0297a32dd8 100644
--- a/notes-to-self/loopy.py
+++ b/notes-to-self/loopy.py
@@ -1,6 +1,8 @@
-import trio
 import time
 
+import trio
+
+
 async def loopy():
     try:
         while True:
@@ -9,10 +11,12 @@ async def loopy():
     except KeyboardInterrupt:
         print("KI!")
 
+
 async def main():
     async with trio.open_nursery() as nursery:
         nursery.start_soon(loopy)
         nursery.start_soon(loopy)
         nursery.start_soon(loopy)
 
+
 trio.run(main)
diff --git a/notes-to-self/lots-of-tasks.py b/notes-to-self/lots-of-tasks.py
index fca2741de9..048c69a7ec 100644
--- a/notes-to-self/lots-of-tasks.py
+++ b/notes-to-self/lots-of-tasks.py
@@ -1,12 +1,15 @@
 import sys
+
 import trio
 
 (COUNT_STR,) = sys.argv[1:]
 COUNT = int(COUNT_STR)
 
+
 async def main():
     async with trio.open_nursery() as nursery:
         for _ in range(COUNT):
             nursery.start_soon(trio.sleep, 1)
 
+
 trio.run(main)
diff --git a/notes-to-self/manual-signal-handler.py b/notes-to-self/manual-signal-handler.py
index 39ffeb5a4b..e1b5ee3036 100644
--- a/notes-to-self/manual-signal-handler.py
+++ b/notes-to-self/manual-signal-handler.py
@@ -3,16 +3,20 @@
 
 if os.name == "nt":
     import cffi
+
     ffi = cffi.FFI()
-    ffi.cdef("""
+    ffi.cdef(
+        """
         void* WINAPI GetProcAddress(void* hModule, char* lpProcName);
         typedef void (*PyOS_sighandler_t)(int);
-    """)
+    """
+    )
     kernel32 = ffi.dlopen("kernel32.dll")
     PyOS_getsig_ptr = kernel32.GetProcAddress(
-        ffi.cast("void*", sys.dllhandle), b"PyOS_getsig")
+        ffi.cast("void*", sys.dllhandle), b"PyOS_getsig"
+    )
     PyOS_getsig = ffi.cast("PyOS_sighandler_t (*)(int)", PyOS_getsig_ptr)
 
-
     import signal
+
     PyOS_getsig(signal.SIGINT)(signal.SIGINT)
diff --git a/notes-to-self/measure-listen-backlog.py b/notes-to-self/measure-listen-backlog.py
index dc32732dfe..b7253b86cc 100644
--- a/notes-to-self/measure-listen-backlog.py
+++ b/notes-to-self/measure-listen-backlog.py
@@ -1,5 +1,6 @@
 import trio
 
+
 async def run_test(nominal_backlog):
     print("--\nnominal:", nominal_backlog)
 
@@ -22,5 +23,6 @@ async def run_test(nominal_backlog):
     for client_sock in client_socks:
         client_sock.close()
 
+
 for nominal_backlog in [10, trio.socket.SOMAXCONN, 65535]:
     trio.run(run_test, nominal_backlog)
diff --git a/notes-to-self/ntp-example.py b/notes-to-self/ntp-example.py
index 44db8cc873..2bb9f80fb3 100644
--- a/notes-to-self/ntp-example.py
+++ b/notes-to-self/ntp-example.py
@@ -3,9 +3,11 @@
 # - use the hostname "2.pool.ntp.org"
 #   (see: https://news.ntppool.org/2011/06/continuing-ipv6-deployment/)
 
-import trio
-import struct
 import datetime
+import struct
+
+import trio
+
 
 def make_query_packet():
     """Construct a UDP packet suitable for querying an NTP server to ask for
@@ -27,6 +29,7 @@ def make_query_packet():
 
     return packet
 
+
 def extract_transmit_timestamp(ntp_packet):
     """Given an NTP packet, extract the "transmit timestamp" field, as a
     Python datetime."""
@@ -49,15 +52,16 @@ def extract_transmit_timestamp(ntp_packet):
     offset = datetime.timedelta(seconds=seconds + fraction / 2**32)
     return base_time + offset
 
+
 async def main():
     print("Our clock currently reads (in UTC):", datetime.datetime.utcnow())
 
     # Look up some random NTP servers.
     # (See www.pool.ntp.org for information about the NTP pool.)
     servers = await trio.socket.getaddrinfo(
-        "pool.ntp.org",               # host
-        "ntp",                        # port
-        family=trio.socket.AF_INET,   # IPv4
+        "pool.ntp.org",  # host
+        "ntp",  # port
+        family=trio.socket.AF_INET,  # IPv4
         type=trio.socket.SOCK_DGRAM,  # UDP
     )
 
@@ -66,7 +70,7 @@ async def main():
 
     # Create a UDP socket
     udp_sock = trio.socket.socket(
-        family=trio.socket.AF_INET,   # IPv4
+        family=trio.socket.AF_INET,  # IPv4
         type=trio.socket.SOCK_DGRAM,  # UDP
     )
 
@@ -88,4 +92,5 @@ async def main():
             transmit_timestamp = extract_transmit_timestamp(data)
             print("Their clock read (in UTC):", transmit_timestamp)
 
+
 trio.run(main)
diff --git a/notes-to-self/proxy-benchmarks.py b/notes-to-self/proxy-benchmarks.py
index a45d94d056..ea92e10c6f 100644
--- a/notes-to-self/proxy-benchmarks.py
+++ b/notes-to-self/proxy-benchmarks.py
@@ -3,6 +3,7 @@
 
 methods = {"fileno"}
 
+
 class Proxy1:
     strategy = "__getattr__"
     works_for = "any attr"
@@ -15,8 +16,10 @@ def __getattr__(self, name):
             return getattr(self._wrapped, name)
         raise AttributeError(name)
 
+
 ################################################################
 
+
 class Proxy2:
     strategy = "generated methods (getattr + closure)"
     works_for = "methods"
@@ -24,16 +27,20 @@ class Proxy2:
     def __init__(self, wrapped):
         self._wrapped = wrapped
 
+
 def add_wrapper(cls, method):
     def wrapper(self, *args, **kwargs):
         return getattr(self._wrapped, method)(*args, **kwargs)
+
     setattr(cls, method, wrapper)
 
+
 for method in methods:
     add_wrapper(Proxy2, method)
 
 ################################################################
 
+
 class Proxy3:
     strategy = "generated methods (exec)"
     works_for = "methods"
@@ -41,20 +48,27 @@ class Proxy3:
     def __init__(self, wrapped):
         self._wrapped = wrapped
 
+
 def add_wrapper(cls, method):
-    code = textwrap.dedent("""
+    code = textwrap.dedent(
+        """
         def wrapper(self, *args, **kwargs):
             return self._wrapped.{}(*args, **kwargs)
-    """.format(method))
+    """.format(
+            method
+        )
+    )
     ns = {}
     exec(code, ns)
     setattr(cls, method, ns["wrapper"])
 
+
 for method in methods:
     add_wrapper(Proxy3, method)
 
 ################################################################
 
+
 class Proxy4:
     strategy = "generated properties (getattr + closure)"
     works_for = "any attr"
@@ -62,6 +76,7 @@ class Proxy4:
     def __init__(self, wrapped):
         self._wrapped = wrapped
 
+
 def add_wrapper(cls, attr):
     def getter(self):
         return getattr(self._wrapped, attr)
@@ -74,11 +89,13 @@ def deleter(self):
 
     setattr(cls, attr, property(getter, setter, deleter))
 
+
 for method in methods:
     add_wrapper(Proxy4, method)
 
 ################################################################
 
+
 class Proxy5:
     strategy = "generated properties (exec)"
     works_for = "any attr"
@@ -86,8 +103,10 @@ class Proxy5:
     def __init__(self, wrapped):
         self._wrapped = wrapped
 
+
 def add_wrapper(cls, attr):
-    code = textwrap.dedent("""
+    code = textwrap.dedent(
+        """
         def getter(self):
             return self._wrapped.{attr}
 
@@ -96,16 +115,21 @@ def setter(self, newval):
 
         def deleter(self):
             del self._wrapped.{attr}
-    """.format(attr=attr))
+    """.format(
+            attr=attr
+        )
+    )
     ns = {}
     exec(code, ns)
     setattr(cls, attr, property(ns["getter"], ns["setter"], ns["deleter"]))
 
+
 for method in methods:
     add_wrapper(Proxy5, method)
 
 ################################################################
 
+
 # methods only
 class Proxy6:
     strategy = "copy attrs from wrappee to wrapper"
@@ -116,17 +140,19 @@ def __init__(self, wrapper):
 
         for method in methods:
             setattr(self, method, getattr(self._wrapper, method))
-    
+
 
 ################################################################
 
 classes = [Proxy1, Proxy2, Proxy3, Proxy4, Proxy5, Proxy6]
 
+
 def check(cls):
     with open("/etc/passwd") as f:
         p = cls(f)
         assert p.fileno() == f.fileno()
 
+
 for cls in classes:
     check(cls)
 
@@ -135,7 +161,7 @@ def check(cls):
 
 COUNT = 1000000
 try:
-    import __pypy__
+    import __pypy__  # noqa: F401  # __pypy__ imported but unused
 except ImportError:
     pass
 else:
@@ -147,8 +173,7 @@ def check(cls):
         start = time.perf_counter()
         for _ in range(COUNT):
             obj.fileno()
-            #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))
+        print("{:7.2f} / us: {} ({})".format(per_usec, obj.strategy, obj.works_for))
diff --git a/notes-to-self/reopen-pipe.py b/notes-to-self/reopen-pipe.py
index 5e5b31e41f..dbccd567d7 100644
--- a/notes-to-self/reopen-pipe.py
+++ b/notes-to-self/reopen-pipe.py
@@ -1,7 +1,7 @@
 import os
+import tempfile
 import threading
 import time
-import tempfile
 
 
 def check_reopen(r1, w):
diff --git a/notes-to-self/schedule-timing.py b/notes-to-self/schedule-timing.py
index 176dcf9220..c84ec9a436 100644
--- a/notes-to-self/schedule-timing.py
+++ b/notes-to-self/schedule-timing.py
@@ -1,6 +1,7 @@
-import trio
 import time
 
+import trio
+
 LOOPS = 0
 RUNNING = True
 
diff --git a/notes-to-self/socket-scaling.py b/notes-to-self/socket-scaling.py
index 1571be4d17..bd7e32ef7f 100644
--- a/notes-to-self/socket-scaling.py
+++ b/notes-to-self/socket-scaling.py
@@ -17,13 +17,16 @@
 #
 # or similar.
 
+import socket
 import time
+
 import trio
 import trio.testing
-import socket
+
 
 async def main():
     for total in [10, 100, 500, 1_000, 10_000, 20_000, 30_000]:
+
         def pt(desc, *, count=total, item="socket"):
             nonlocal last_time
             now = time.perf_counter()
@@ -53,4 +56,5 @@ def pt(desc, *, count=total, item="socket"):
             sock.close()
         pt("closing sockets")
 
+
 trio.run(main)
diff --git a/notes-to-self/ssl-close-notify/ssl-close-notify.py b/notes-to-self/ssl-close-notify/ssl-close-notify.py
index cd4b450de8..32ecbea2f0 100644
--- a/notes-to-self/ssl-close-notify/ssl-close-notify.py
+++ b/notes-to-self/ssl-close-notify/ssl-close-notify.py
@@ -22,6 +22,7 @@
 
 client_done = threading.Event()
 
+
 def server_thread_fn():
     server_ctx = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)
     server_ctx.load_cert_chain("trio-test-1.pem")
@@ -42,13 +43,12 @@ def server_thread_fn():
             break
         server.sendall(data)
 
+
 server_thread = threading.Thread(target=server_thread_fn)
 server_thread.start()
 
 client_ctx = ssl.create_default_context(cafile="trio-test-CA.pem")
-client = client_ctx.wrap_socket(
-    client_sock,
-    server_hostname="trio-test-1.example.org")
+client = client_ctx.wrap_socket(client_sock, server_hostname="trio-test-1.example.org")
 
 
 # Now we have two SSLSockets that have established an encrypted connection
diff --git a/notes-to-self/ssl-close-notify/ssl2.py b/notes-to-self/ssl-close-notify/ssl2.py
index 32a68e1495..54ee1fb9b6 100644
--- a/notes-to-self/ssl-close-notify/ssl2.py
+++ b/notes-to-self/ssl-close-notify/ssl2.py
@@ -5,7 +5,7 @@
 import ssl
 import threading
 
-#client_sock, server_sock = socket.socketpair()
+# client_sock, server_sock = socket.socketpair()
 listen_sock = socket.socket()
 listen_sock.bind(("127.0.0.1", 0))
 listen_sock.listen(1)
@@ -52,12 +52,12 @@
 server.shutdown(socket.SHUT_WR)
 
 # Attempting to read/write to the fd after it's closed should raise EBADF
-#os.close(server.fileno())
+# os.close(server.fileno())
 
 # Attempting to read/write to an fd opened with O_DIRECT raises EINVAL in most
 # cases (unless you're very careful with alignment etc. which openssl isn't)
-#os.dup2(os.open("/tmp/blah-example-file", os.O_RDWR | os.O_CREAT | os.O_DIRECT), server.fileno())
+# os.dup2(os.open("/tmp/blah-example-file", os.O_RDWR | os.O_CREAT | os.O_DIRECT), server.fileno())
 
 # Sending or receiving
 server.sendall(b"hello")
-#server.recv(10)
+# server.recv(10)
diff --git a/notes-to-self/ssl-handshake/ssl-handshake.py b/notes-to-self/ssl-handshake/ssl-handshake.py
index 18a0e1a675..e906bc2a87 100644
--- a/notes-to-self/ssl-handshake/ssl-handshake.py
+++ b/notes-to-self/ssl-handshake/ssl-handshake.py
@@ -1,5 +1,5 @@
-import ssl
 import socket
+import ssl
 import threading
 from contextlib import contextmanager
 
diff --git a/notes-to-self/sslobject.py b/notes-to-self/sslobject.py
index 0692af319c..a6e7b07a08 100644
--- a/notes-to-self/sslobject.py
+++ b/notes-to-self/sslobject.py
@@ -1,5 +1,5 @@
-from contextlib import contextmanager
 import ssl
+from contextlib import contextmanager
 
 client_ctx = ssl.create_default_context(ssl.Purpose.SERVER_AUTH)
 client_ctx.check_hostname = False
diff --git a/notes-to-self/thread-dispatch-bench.py b/notes-to-self/thread-dispatch-bench.py
index 9afb4bbec8..70547a6000 100644
--- a/notes-to-self/thread-dispatch-bench.py
+++ b/notes-to-self/thread-dispatch-bench.py
@@ -5,8 +5,8 @@
 # trio.to_thread.run_sync
 
 import threading
-from queue import Queue
 import time
+from queue import Queue
 
 COUNT = 10000
 
diff --git a/notes-to-self/time-wait.py b/notes-to-self/time-wait.py
index 08c71b0048..772f6c2727 100644
--- a/notes-to-self/time-wait.py
+++ b/notes-to-self/time-wait.py
@@ -26,8 +26,8 @@
 # Also, it must be set on listen2 before calling bind(), or it will conflict
 # with the lingering server1 socket.
 
-import socket
 import errno
+import socket
 
 import attr
 
diff --git a/notes-to-self/trace.py b/notes-to-self/trace.py
index c024a36ba5..aa68fac125 100644
--- a/notes-to-self/trace.py
+++ b/notes-to-self/trace.py
@@ -1,8 +1,9 @@
-import trio
-import os
 import json
+import os
 from itertools import count
 
+import trio
+
 # Experiment with generating Chrome Event Trace format, which can be browsed
 # through chrome://tracing or other mechanisms.
 #
@@ -29,6 +30,7 @@
 #   let us also show "task is running", because neither kind of event is
 #   strictly nested inside the other
 
+
 class Trace(trio.abc.Instrument):
     def __init__(self, out):
         self.out = out
@@ -108,14 +110,14 @@ def task_scheduled(self, task):
 
     def before_io_wait(self, timeout):
         self._write(
-            name=f"I/O wait",
+            name="I/O wait",
             ph="B",
             tid=-1,
         )
 
     def after_io_wait(self, timeout):
         self._write(
-            name=f"I/O wait",
+            name="I/O wait",
             ph="E",
             tid=-1,
         )
@@ -126,11 +128,13 @@ async def child1():
     await trio.sleep(1)
     print("  child1: exiting!")
 
+
 async def child2():
     print("  child2: started! sleeping now...")
     await trio.sleep(1)
     print("  child2: exiting!")
 
+
 async def parent():
     print("parent: started!")
     async with trio.open_nursery() as nursery:
@@ -144,5 +148,6 @@ async def parent():
         # -- we exit the nursery block here --
     print("parent: all done!")
 
+
 t = Trace(open("/tmp/t.json", "w"))
 trio.run(parent, instruments=[t])
diff --git a/notes-to-self/trivial-err.py b/notes-to-self/trivial-err.py
index ed11ec33e6..6c32617c74 100644
--- a/notes-to-self/trivial-err.py
+++ b/notes-to-self/trivial-err.py
@@ -1,26 +1,33 @@
 import sys
+
 import trio
 
 sys.stderr = sys.stdout
 
+
 async def child1():
     raise ValueError
 
+
 async def child2():
     async with trio.open_nursery() as nursery:
         nursery.start_soon(grandchild1)
         nursery.start_soon(grandchild2)
 
+
 async def grandchild1():
     raise KeyError
 
+
 async def grandchild2():
     raise NameError("Bob")
 
+
 async def main():
     async with trio.open_nursery() as nursery:
         nursery.start_soon(child1)
         nursery.start_soon(child2)
-        #nursery.start_soon(grandchild1)
+        # nursery.start_soon(grandchild1)
+
 
 trio.run(main)
diff --git a/notes-to-self/trivial.py b/notes-to-self/trivial.py
index 6852d63200..405d92daf5 100644
--- a/notes-to-self/trivial.py
+++ b/notes-to-self/trivial.py
@@ -1,8 +1,10 @@
 import trio
 
+
 async def foo():
     print("in foo!")
     return 3
 
+
 print("running!")
 print(trio.run(foo))
diff --git a/notes-to-self/wakeup-fd-racer.py b/notes-to-self/wakeup-fd-racer.py
index c6ef6caec1..b56cbdc91c 100644
--- a/notes-to-self/wakeup-fd-racer.py
+++ b/notes-to-self/wakeup-fd-racer.py
@@ -1,19 +1,21 @@
+import itertools
 import os
+import select
 import signal
+import socket
 import threading
 import time
-import socket
-import select
-import itertools
 
 # Equivalent to the C function raise(), which Python doesn't wrap
 if os.name == "nt":
     import cffi
+
     _ffi = cffi.FFI()
     _ffi.cdef("int raise(int);")
     _lib = _ffi.dlopen("api-ms-win-crt-runtime-l1-1-0.dll")
     signal_raise = getattr(_lib, "raise")
 else:
+
     def signal_raise(signum):
         # Use pthread_kill to make sure we're actually using the wakeup fd on
         # Unix
@@ -26,7 +28,7 @@ def raise_SIGINT_soon():
     # Sending 2 signals becomes reliable, as we'd expect (because we need
     # set-flags -> write-to-fd, and doing it twice does
     # write-to-fd -> set-flags -> write-to-fd -> set-flags)
-    #signal_raise(signal.SIGINT)
+    # signal_raise(signal.SIGINT)
 
 
 def drain(sock):
@@ -87,8 +89,10 @@ def main():
         # them.
         duration = time.perf_counter() - start
         if duration < 2:
-            print(f"Attempt {attempt}: OK, trying again "
-                  f"(select_calls = {select_calls}, drained = {drained})")
+            print(
+                f"Attempt {attempt}: OK, trying again "
+                f"(select_calls = {select_calls}, drained = {drained})"
+            )
         else:
             print(f"Attempt {attempt}: FAILED, took {duration} seconds")
             print(f"select_calls = {select_calls}, drained = {drained}")
@@ -96,5 +100,6 @@ def main():
 
         thread.join()
 
+
 if __name__ == "__main__":
     main()
diff --git a/notes-to-self/win-waitable-timer.py b/notes-to-self/win-waitable-timer.py
index 92bfd7a39a..5309f43867 100644
--- a/notes-to-self/win-waitable-timer.py
+++ b/notes-to-self/win-waitable-timer.py
@@ -24,12 +24,12 @@
 # make this fairly straightforward, but you obviously need to use a separate
 # time source
 
-import cffi
 from datetime import datetime, timedelta, timezone
-import time
+
+import cffi
 
 import trio
-from trio._core._windows_cffi import (ffi, kernel32, raise_winerror)
+from trio._core._windows_cffi import ffi, kernel32, raise_winerror
 
 try:
     ffi.cdef(
@@ -91,7 +91,7 @@
   LPFILETIME       lpFileTime
 );
 """,
-    override=True
+    override=True,
 )
 
 ProcessLeapSecondInfo = 8
@@ -106,10 +106,10 @@ def set_leap_seconds_enabled(enabled):
         plsi.Flags = 0
     plsi.Reserved = 0
     if not kernel32.SetProcessInformation(
-            ffi.cast("HANDLE", -1),  # current process
-            ProcessLeapSecondInfo,
-            plsi,
-            ffi.sizeof("PROCESS_LEAP_SECOND_INFO"),
+        ffi.cast("HANDLE", -1),  # current process
+        ProcessLeapSecondInfo,
+        plsi,
+        ffi.sizeof("PROCESS_LEAP_SECOND_INFO"),
     ):
         raise_winerror()
 
@@ -135,9 +135,7 @@ def now_as_filetime():
 #   https://www.epochconverter.com/ldap
 #
 FILETIME_TICKS_PER_SECOND = 10**7
-FILETIME_EPOCH = datetime.strptime(
-    '1601-01-01 00:00:00 Z', '%Y-%m-%d %H:%M:%S %z'
-)
+FILETIME_EPOCH = datetime.strptime("1601-01-01 00:00:00 Z", "%Y-%m-%d %H:%M:%S %z")
 # XXX THE ABOVE IS WRONG:
 #
 #   https://techcommunity.microsoft.com/t5/networking-blog/leap-seconds-for-the-appdev-what-you-should-know/ba-p/339813#
@@ -159,11 +157,9 @@ def now_as_filetime():
 
 def py_datetime_to_win_filetime(dt):
     # We'll want to call this on every datetime as it comes in
-    #dt = dt.astimezone(timezone.utc)
+    # dt = dt.astimezone(timezone.utc)
     assert dt.tzinfo is timezone.utc
-    return round(
-        (dt - FILETIME_EPOCH).total_seconds() * FILETIME_TICKS_PER_SECOND
-    )
+    return round((dt - FILETIME_EPOCH).total_seconds() * FILETIME_TICKS_PER_SECOND)
 
 
 async def main():
diff --git a/pyproject.toml b/pyproject.toml
index 073e2508d1..97970f0ed0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,11 @@
 [tool.black]
 target-version = ['py38']
+force-exclude = '''
+(
+  ^/docs/source/reference-.*
+  | ^/docs/source/tutorial
+)
+'''
 
 [tool.codespell]
 ignore-words-list = 'astroid,crasher,asend'
@@ -20,6 +26,10 @@ per-file-ignores = [
 combine_as_imports = true
 profile = "black"
 skip_gitignore = true
+skip_glob = [
+  "docs/source/reference-*",
+  "docs/source/tutorial/*"
+]
 
 [tool.mypy]
 python_version = "3.8"