manager.py 文件源码

def webdriver(self):
        """Return the webdriver instance, instantiate it if necessary."""
        if self._webdriver is None:
            short_arg_classes = (webdriver.Firefox, webdriver.Ie)
            if issubclass(self._browser, short_arg_classes):
                cap_attr = 'capabilities'
            else:
                cap_attr = 'desired_capabilities'
            options = self._options
            options[cap_attr] = self._desired_capabilities
            self._webdriver = self._browser(**options)
            self._webdriver.set_window_size(settings.DRIVER_WINDOW_WIDTH, settings.DRIVER_WINDOW_HEIGHT)
            self._webdriver.set_page_load_timeout(self.crawler.settings.get('DOMAIN_TIMEOUT', 30))
            self.crawler.signals.connect(self._cleanup, signal=engine_stopped)
        return self._webdriver