Strange formatting difference when running python 3.6 versus 3.7

[njsmith]

Here's some code:

class Blah:
    async def __anext__(self):
        return { await self._signal_queue.__anext__()}

Notice the weird space before the await.

According to yapf 0.24.0 (and earlier), when running on python 3.6, this code is formatted correctly:

/tmp$ p36/bin/yapf --version  
yapf 0.24.0
/tmp$ p36/bin/python --version
Python 3.6.5
/tmp$ p36/bin/yapf -d asdf.py    

According to yapf 0.24.0 (and earlier), when running on python 3.7, this code is formatted incorrectly:

/tmp$ p37/bin/yapf --version
yapf 0.24.0
/tmp$ p37/bin/python --version
Python 3.7.0b3
/tmp$ p37/bin/yapf -d asdf.py 
--- asdf.py	(original)
+++ asdf.py	(reformatted)
@@ -1,3 +1,3 @@
 class Blah:
     async def __anext__(self):
-        return { await self._signal_queue.__anext__()}
+        return {await self._signal_queue.__anext__()}

This leads to frustration when some members of a team are using python 3.6, and some are using 3.7.

[kamahen]

This could be the reason (changes between Python 3.6 and 3.7 <https://docs.python.org/3/whatsnew/3.7.html>): Backwards incompatible syntax changes: - async <https://docs.python.org/3/reference/compound_stmts.html#async> and await <https://docs.python.org/3/reference/expressions.html#await> are now reserved keywords.

…

On Fri, 28 Sep 2018 at 00:53, Nathaniel J. Smith ***@***.***> wrote: Here's some code: class Blah: async def __anext__(self): return { await self._signal_queue.__anext__()} Notice the weird space before the await. According to yapf 0.24.0 (and earlier), when running on python 3.6, this code is formatted correctly: /tmp$ p36/bin/yapf --version yapf 0.24.0 /tmp$ p36/bin/python --version Python 3.6.5 /tmp$ p36/bin/yapf -d asdf.py According to yapf 0.24.0 (and earlier), when running on python 3.7, this code is formatted *in*correctly: /tmp$ p37/bin/yapf --version yapf 0.24.0 /tmp$ p37/bin/python --version Python 3.7.0b3 /tmp$ p37/bin/yapf -d asdf.py --- asdf.py (original) +++ asdf.py (reformatted) @@ -1,3 +1,3 @@ class Blah: async def __anext__(self): - return { await self._signal_queue.__anext__()} + return {await self._signal_queue.__anext__()} This leads to frustration when some members of a team are using python 3.6, and some are using 3.7. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#624>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AhBmtb7uWLcCbKfT6ZFhLU-qpAcviX4Zks5ufdV2gaJpZM4W-BYd> .