ImportError: cannot import name 'hdrs'

[sbhadr]

Long story short

Aiohttp is unusable when imported on Python 3.5.

Expected behaviour

Normal usage.

Actual behaviour

ImportError: cannot import name 'hdrs' when importing aiohttp.

Steps to reproduce

import aiohttp

Your environment

Windows 10, Python 3.5

Error Log

Traceback (most recent call last):
  File "cc.py", line 1, in <module>
    from pyblox import *
  File "C:\Users\sanja\AppData\Local\Programs\Python\Python35\lib\site-packages\pyblox\__init__.py", line 16, in <module>
    from .api.assets import Assets
  File "C:\Users\sanja\AppData\Local\Programs\Python\Python35\lib\site-packages\pyblox\api\assets.py", line 9, in <module>
    from .http import Http
  File "C:\Users\sanja\AppData\Local\Programs\Python\Python35\lib\site-packages\pyblox\api\http.py", line 11, in <module>
    import aiohttp
  File "C:\Users\sanja\AppData\Roaming\Python\Python35\site-packages\aiohttp\__init__.py", line 9, in <module>
    from . import hdrs  # noqa
ImportError: cannot import name 'hdrs'

[asvetlov]

GitMate.io thinks possibly related issues are #849 (Example Server Fails to Run with "ImportError: cannot import name 'InvalidURL'"), #843 (ImportError: No module named 'aiohttp'), #2662 (ImportError: cannot import name 'unquote'), #1447 (ImportError: cannot import name 'quote'), and #936 (ImportError: No modile named 'http.server' when I try to run pytests).

[asvetlov]

The minimal supported version is Python 3.5.3
If you have it at least -- aiohttp works, we run tests for Python 3.5 on Windows box explicitly

[sbhadr]

Import Error on call is not exactly my conception of "working". Any reason as to why Python 3.5.3 is supported but not Python 3.5 ?

[asvetlov]

aiohttp relies on features introduced in Python 3.5.3
Do you use older Python?

[sbhadr]

Yes, Python 3.5. Could you be specific as to which features introduced in Python 3.5.3 ?

[asvetlov]

Python 3.5.X
What is X on your box?
If your pip version is not too old the tool cannot install aiohttp 3.x on not compatible Python, e.g. 3.5.2

[sbhadr]

Python 3.5.X What is X on your box?
Python 3.5.0

If your pip version is not too old the tool cannot install aiohttp 3.x on not compatible Python, e.g. 3.5.2
Pip is up to date.

Could you be specific as to which features introduced in Python 3.5.3 ?

[asvetlov]

Up-to-date pip means pip --version is something like 18.0.
It respects python-requires argument from metadata: https://github.com/aio-libs/aiohttp/blob/master/setup.py#L148

There are many changes: transport.set_protocol() and __aiter__ signature for example.
The most notable change is: asyncio.get_event_loop() is reliable.
If called from async function the returned value is an active (running) loop, not the loop specified by asyncio.set_event_loop() call.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a [new issue] for related bugs.
If you feel like there's important points made in this discussion, please include those exceprts into that [new issue].
[new issue]: https://github.com/aio-libs/aiohttp/issues/new