<filename>client/apps.py
from django.apps import AppConfig
from django.utils.translation import ugettext_lazy as _


class ClientConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'client'
    verbose_name = _('Client')

    def ready(self):
        pass
        # import  client.signals

<filename>client/apps.py
from django.apps import AppConfig
from django.utils.translation import ugettext_lazy as _


class ClientConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'client'
    verbose_name = _('Client')

    def ready(self):
        pass
        # import  client.signals

# import  client.signals