def from_crawler(cls, crawler: Crawler):
base_settings: BaseSettings = crawler.settings
cls.normalize(base_settings)
settings = BaseSettings(priority='spider')
cls.from_object(settings, crawler.spidercls.SpiderConfig)
settings.update(
{k: v
for k, v in base_settings.items() if k in settings},
priority='cmdline')
preset = base_settings.get('PRESET')
if preset:
preset_dict = BaseSettings(priority=35)
cls.from_pyfile(preset_dict, preset)
settings.update(preset_dict)
adapted = BaseSettings(priority=50)
for k, v in settings.items():
adapt = getattr(SettingsAdapter, k.lower(), None)
if adapt:
adapted.update(adapt(v))
else:
adapted[k] = v
base_settings.update(adapted.copy_to_dict(), priority=50)
base_settings['SPIDER_CONFIG'] = adapted
return cls()
