urequests: Compatibility with CPython

[amotl]

Hi there,

when invoking the urequests module on CPython, it will croak with

TypeError: %b requires a bytes-like object, or an object that implements __bytes__, not 'str'

when starting to write to the socket stream:

s.write(b"%s /%s HTTP/1.0\r\n" % (method, path))

This has also been reported on adafruit/Adafruit_CircuitPython_Requests#10 and was fixed by adafruit/Adafruit_CircuitPython_Requests#11.

With kind regards,
Andreas.

[mattytrentini]

@andrewleech I think this is also still valid for urequests though I haven't tried it on CPython.

[andrewleech]

urequests is currently not really compatible with CPython at all.
For a start, the import would need to handle usocket vs socket, then on cpython there is no socket.write function, only socket.send.

Whether urequests should be compatible with cpython is an interesting discussion, which there could be conveniences to being able to test code in cpython, not much of the micropython-lib codebase would be compatible currently.

Separately to that, the micropython b"%s" % str clearly has an auto-convert which cpython does not support - I guess this is a confusing difference between the platforms, though I feel it's one of many cases micropython is more "tolerant" of things than cpython.

While that patch from circuitpython works to avoid the b"%s" % str error on CPython, it does add extra code (flash&ram) to the module that is not technically needed on micropython currently, so I'm not sure it's really worth adding?

[dpgeorge]

I don't think it's worth supporting urequests (or any other library in this repo) running under CPython. That would be too restrictive and not allow us to implement things in an efficient way.