Switch to black

check.sh

@@ -5,7 +5,7 @@ set -ex
 EXIT_STATUS=0
 
 # Autoformatter *first*, to avoid double-reporting errors
-yapf -rpd setup.py trio \
+black --diff setup.py trio \
     || EXIT_STATUS=$?
 
 # Run flake8 without pycodestyle and import-related errors
@@ -23,7 +23,7 @@ Problems were found by static analysis (listed above).
 To fix formatting and see remaining errors, run
 
     pip install -r test-requirements.txt
-    yapf -rpi setup.py trio
+    black setup.py trio
     ./check.sh
 
 in your local checkout.

docs/source/contributing.rst

@@ -130,7 +130,7 @@ in separate sections below:
   adding a test to make sure it stays fixed.
 
 * :ref:`pull-request-formatting`: If you changed Python code, then did
-  you run ``yapf -rpi setup.py trio``? (Or for other packages, replace
+  you run ``black setup.py trio``? (Or for other packages, replace
   ``trio`` with the package name.)
 
 * :ref:`pull-request-release-notes`: If your change affects
@@ -273,31 +273,27 @@ of eyes can be helpful when trying to come up with devious tricks.
 Code formatting
 ~~~~~~~~~~~~~~~
 
-Instead of wasting time arguing about code formatting, we use `yapf
-<https://github.com/google/yapf>`__ to automatically format all our
+Instead of wasting time arguing about code formatting, we use black`
+<https://github.com/ambv/black>`__ to automatically format all our
 code to a standard style. While you're editing code you can be as
 sloppy as you like about whitespace; and then before you commit, just
 run::
 
-    pip install -U yapf
-    yapf -rpi setup.py trio
+    pip install -U black
+    black setup.py trio
 
 to fix it up. (And don't worry if you forget – when you submit a pull
 request then we'll automatically check and remind you.) Hopefully this
 will let you focus on more important style issues like choosing good
 names, writing useful comments, and making sure your docstrings are
-nicely formatted. (Yapf doesn't reformat comments or docstrings.)
+nicely formatted. (black doesn't reformat comments or docstrings.)
 
-Very occasionally, yapf will generate really ugly and unreadable
-formatting (usually for large literal structures like dicts nested
-inside dicts). In these cases, you can add a ``# yapf: disable``
-comment to tell it to leave that particular statement alone.
+If you want to see what changes black will make, you can use::
 
-If you want to see what changes yapf will make, you can use::
+  black --diff setup.py trio
 
-  yapf -rpd setup.py trio
-
-(``-d`` displays a diff, versus ``-i`` which fixes files in-place.)
+(``--diff`` displays a diff, versus the default mode which fixes files
+in-place.)
 
 
 .. _pull-request-release-notes:

setup.py

@@ -82,7 +82,7 @@
         "sniffio",
         # PEP 508 style, but:
         # https://bitbucket.org/pypa/wheel/issues/181/bdist_wheel-silently-discards-pep-508
-        #"cffi; os_name == 'nt'",  # "cffi is required on windows"
+        # "cffi; os_name == 'nt'",  # "cffi is required on windows"
     ],
     # This means, just install *everything* you see under trio/, even if it
     # doesn't look like a source file, so long as it appears in MANIFEST.in:
@@ -93,7 +93,7 @@
     # recent
     extras_require={
         ":os_name == 'nt'": ["cffi"],  # "cffi is required on windows",
-        ":python_version < '3.7'": ["contextvars>=2.1"]
+        ":python_version < '3.7'": ["contextvars>=2.1"],
     },
     python_requires=">=3.5",
     keywords=["async", "io", "networking", "trio"],

test-requirements.in

@@ -9,7 +9,7 @@ pylint         # for pylint finding all symbols tests
 jedi           # for jedi code completion tests
 
 # Tools
-yapf == 0.24.0  # formatting
+black;python_version>="3.6"  # formatting
 flake8
 
 # https://github.com/python-trio/trio/pull/654#issuecomment-420518745

test-requirements.txt

@@ -4,12 +4,16 @@
 #
 #    pip-compile --output-file test-requirements.txt test-requirements.in
 #
+appdirs==1.4.3            # via black
+appnope==0.1.0            # via ipython
 asn1crypto==0.24.0        # via cryptography
 astroid==2.0.4            # via pylint
 atomicwrites==1.2.1       # via pytest
-attrs==18.2.0             # via pytest
+attrs==18.2.0             # via black, pytest
 backcall==0.1.0           # via ipython
+black==18.9b0 ; python_version >= "3.6"
 cffi==1.11.5              # via cryptography
+click==7.0                # via black
 coverage==4.5.1           # via pytest-cov
 cryptography==2.3.1       # via pyopenssl, trustme
 decorator==4.3.0          # via ipython, traitlets
@@ -39,9 +43,9 @@ pytest-cov==2.6.0
 pytest-faulthandler==1.5.0
 pytest==3.10.0
 six==1.11.0               # via astroid, cryptography, more-itertools, prompt-toolkit, pyopenssl, pytest, traitlets
+toml==0.10.0              # via black
 traitlets==4.3.2          # via ipython
 trustme==0.4.0
 typed-ast==1.1.0 ; python_version < "3.7" and implementation_name == "cpython"
 wcwidth==0.1.7            # via prompt-toolkit
 wrapt==1.10.11            # via astroid
-yapf==0.24.0