The object is created
Selector located scrapy.selector achieve class module Selector object created when a document can be passed Html page string constructor method to Selector
2, select the data
Calls Selector object xpath or css method (incoming xpath or css selector expression), you can select a certain part of the document
xpath and css method returns a SelectorList objects, each of which comprises a portion corresponding to the selected Selector object, SelectorList list of interfaces supported, for loop iterations may be used to access each of the objects Selector
3, extract information
Selector call or SelectorList object method can extract the selected content
extract
The method will extract all the results collected SelectorList object to a list is returned to the user
re
Use regular expressions to extract the desired content
extract_first
Selector object returns the first result of calling the extract method. SelectorList object usually contains only a Selector object when this method is invoked
re_first