def overridden_settings(settings):
    """Return a dict of the settings that have been overridden"""
    for name, defvalue in iter_default_settings():
        value = settings[name]
        if not isinstance(defvalue, dict) and value != defvalue:
            yield name, value
Return a dict of the settings that have been overridden
stackoverflow/venv/lib/python3.6/site-packages/scrapy/settings/__init__.py