OAuth2Session token not preserved when copied to multiple processes

[ruscur]

This is a pretty confusing behaviour, so it's quite possible that this isn't a bug at all, but I figured I'd share it anyway.

The behaviour is as follows:

1. An OAuth2Session is created, fetch_token is called, and protected resources can be accessed.
2. Multiple processes (using multiprocessing.Pool) are created to execute a function with this OAuth2Session as a parameter.
3. The token attribute of this OAuth2Session no longer exists within the memory of these new processes.

It's not a big deal because it just requires each process to fetch the token of their OAuth2Session, but it seems like it should "just work".

[Lukasa]

The general rule in Requests is that Session objects should not be shared across threads. They have access to some state that requires synchronisation and they don't synchronise on it.

[ib-lundgren]

A side note. The fetch_token method returns a dict which you should be ok sharing over the processes

>>> token = fetch_token(.....)
{ "token": "abc...", "token_type": "Bearer", ....}

>>> # Inside the new process
>>> session = OAuth2Session("client_id", token=token)