[Python-Dev] async/await in Python; v2 (original) (raw)

MRAB python at mrabarnett.plus.com
Thu Apr 23 20:21:08 CEST 2015

On 2015-04-23 18:51, Barry Warsaw wrote:

On Apr 21, 2015, at 01:26 PM, Yury Selivanov wrote:

The updated version of the PEP should be available shortly at https://www.python.org/dev/peps/pep-0492 and is also pasted in this email. There's a lot to like about PEP 492. I only want to mildly bikeshed a bit on the proposed new syntax. Why "async def" and not "def async"? My concern is about existing tools that already know that "def" as the first non-whitespace on the line starts a function/method definition. Think of a regexp in an IDE that searches backwards from the current line to find the function its defined on. Sure, tools can be updated but it is it necessary to choose a syntax that breaks tools? def async useful(): seems okay to me. Probably the biggest impact on the PEP would be symmetry with asynchronous with and for. What about: with async lock: and for async data in cursor: That would also preserve at least some behavior of existing tools. Anyway, since the PEP doesn't explicitly describe this as an alternative, I want to bring it up. (I have mild concerns about a* magic methods, since I think they'll be harder to visually separate, but here the PEP does describe the async* alternatives.) On the other hand, existing tools might be expecting "def" and "for" to be followed by a name.

More information about the Python-Dev mailing list