pytest

DO

import pytest

@pytest.fixture
def my_ficture():
    ...

DONT

from pytest import fixture

@fixture
def my_ficture():
    ...

datetime

DO

from datetime import datetime, timedelta
delay = datetime.now() + timedelta(hours=1)

DONT

import datetime
delay = datetime.datetime.now() + datetime.timedelta(hours=1)

ALWAYS DO

from __future__ import annotations

__init__.py should not contain code, but __all__
at a package level (router for example) we have one file per system (configuration.py for example)
If we need more files (think of jobs, which have the sandbox, the joblogging, etc), we put them in a sub module (e.g routers.job). The code goes in a specific file (job.py, joblogging.py) but we use the the init.py to expose the specific file