Books about web scraping and data processing
"Web Scraping with Python" by Ryan Mitchell, June 2015
"Mining the Social Web" by Matthew A. Russell
"Web Crawling and Data Mining with Apache Nutch" by Abdulbasit Fazalmehmod Shaikh,Zakir Laliwala Dr Zakir Laliwala
"Learning Scrapy" by Dimitrios Kouzis-Loukas