utils.py 文件源码

def enable(self):
        # Keep this code at the beginning to leave the settings unchanged
        # in case it raises an exception because INSTALLED_APPS is invalid.
        if 'INSTALLED_APPS' in self.options:
            try:
                apps.set_installed_apps(self.options['INSTALLED_APPS'])
            except Exception:
                apps.unset_installed_apps()
                raise
        override = UserSettingsHolder(settings._wrapped)
        for key, new_value in self.options.items():
            setattr(override, key, new_value)
        self.wrapped = settings._wrapped
        settings._wrapped = override
        for key, new_value in self.options.items():
            setting_changed.send(sender=settings._wrapped.__class__,
                                 setting=key, value=new_value, enter=True)