Use buffering=0 for local device

[phako]

Fixes an issue when opening the device read/write:

io.UnsupportedOperation: File or stream is not seekable.

[rosjat]

@phako I get the reason to set the buffering there but I dont think its a good way to do it as a default this way. In genral I would leave the buffering on and make it an option to to switch it off.

so in my opinion, to not break it for older version, we could add a key word arg in init with a default that leaves buffering in place. So someone who wants no buffering can pass it in and it gets set in the open () method.

@sahlberg and @Flameeyes might can give there 5 cent about it too

[phako]

What I understood from https://bugs.python.org/issue20074 is writing cannot work without specifying buffering=0 on python3 but maybe I got that wrong?

[rosjat]

this bug seems to apply to linux yes, and it seems not to be fixed but as I said before just because its something that doesnt work as expected we shouldnt make changes that restrict us from control it. So I would go for the suggested approach and in the end it wont break our code and still give ppl the ability to change it later on if this issue by python gets resolved in the future.

[phako]

Apologies, somewhat got distracted, will provide updated patch later today

[rosjat]

@phako thanks for the contribution, could update the doc strings too please so it refelects your changes made to the args.

cheers

Markus

[phako]

The code is wrong - while looking at the documentation the implementation now sets the buffer to 1 byte which is probably also not what you want. Will come back with a better solution