[Python-ideas] Improving fn(arg=arg, name=name, wibble=wibble) code

[Terry Reedy]

On 9/8/2018 7:17 AM, Jonathan Fine wrote:
> I thank Steve D'Aprano for pointing me to this real-life (although
> perhaps extreme) code example
> 
> https://github.com/Tinche/aiofiles/blob/master/aiofiles/threadpool/__init__.py#L17-L37
> <code>
> def open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None,
>           closefd=True, opener=None, *, loop=None, executor=None):
>      return AiofilesContextManager(_open(file, mode=mode, buffering=buffering,
>                                          encoding=encoding, errors=errors,
>                                          newline=newline, closefd=closefd,
>                                          opener=opener, loop=loop,
>                                          executor=executor))

Given that open and _open, likely written at the same time, have the 
same signature, I would have written the above as the slightly faster call
     return AiofilesContextManager(_open(
             file, mode, buffering, encoding, errors, newline,
             closefd, opener, loop=loop, executor=executor))

> @asyncio.coroutine
> def _open(file, mode='r', buffering=-1, encoding=None, errors=None,
> newline=None,
>            closefd=True, opener=None, *, loop=None, executor=None):
>      """Open an asyncio file."""
>      if loop is None:
>          loop = asyncio.get_event_loop()
>      cb = partial(sync_open, file, mode=mode, buffering=buffering,
>                   encoding=encoding, errors=errors, newline=newline,
>                   closefd=closefd, opener=opener)
>      f = yield from loop.run_in_executor(executor, cb)
> 
>      return wrap(f, loop=loop, executor=executor)
> </code>

-- 
Terry Jan Reedy