in [ ]put_data parse_options_data(putsin [ ]call_data[: out[ ]strike symbol aapl aapl aapl aapl aapl aapl aapl aapl aapl aapl last chg bid ask vol open int / / parsing xml with lxml objectify xml (extensible markup languageis another common structured data format supporting hierarchicalnested data with metadata the files that generate the book you are reading actually form series of large xml documents abovei showed the lxml library and its lxml html interface here show an alternate interface that' convenient for xml datalxml objectify the new york metropolitan transportation authority (mtapublishes number of data series about its bus and train services htmlhere we'll look at the performance data which is contained in set of xml files each train or bus service has different file (like performance_mnr xml for the metronorth railroadcontaining monthly data as series of xml records that look like this metro-north railroad escalator availability percent of the time that escalators are operational systemwide the availability rate is based on physical observations performed the morning of regular business days only this is new indicator the agency began reporting in service indicators reading and writing data in text format www it-ebooks info