generic uwsgi spooler minimal wrapper poc, base of django-uwsgi-spooler (halted) and django-call (ongoing)

uwsgi_spooler.py

from importlib import import_module
import pickle
from uuid import uuid4

try:
    from uwsgi import SPOOL_OK
except ImportError:
    SPOOL_OK = True

try:
    import uwsgi
except ImportError:
    uwsgi = None


def import_string(dotted_path):
    """
    Import a dotted module path and return the attribute/class designated by the
    last name in the path. Raise ImportError if the import failed.
    """
    try:
        module_path, class_name = dotted_path.rsplit('.', 1)
    except ValueError as err:
        raise ImportError("%s doesn't look like a module path" % dotted_path) from err

    module = import_module(module_path)

    try:
        return getattr(module, class_name)
    except AttributeError as err:
        raise ImportError('Module "%s" does not define a "%s" attribute/class' % (
            module_path, class_name)
        )

def emit(callback_name, **env):
    new_env = {
        b'uuid': uuid4(),
        b'callback': callback_name,
        b'body': pickle.dumps(env)
    }

    spool = getattr(uwsgi, 'spooler', spooler)
    spool(new_env)


def spooler(env):
    callback = import_string(env[b'callback'])
    cb_env = pickle.loads(env[b'body'])
    cb_env['uuid'] = env[b'uuid']
    callback(**cb_env)
    return SPOOL_OK


if uwsgi:
    uwsgi.spooler = spooler