Maybe you should give a try at Portia (http://scrapinghub.com/portia/ http://scrapinghub.com/portia/). It does exactly what you mean. You may also be intereste

Maybe you should give a try at Portia (http://scrapinghub.com/portia/ http://scrapinghub.com/portia/). It does exactly what you mean. You may also be interested in this library: https://github.com/scrapy/scrapely https://github.com/scrapy/scrapely