python如何根据给定的KEY分组

python如何根据给定的KEY分组

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根据给定的KEY分组(itertools.groupby)

>>>fromoperatorimportitemgetter>>>importitertools>>>withopen("contactlenses.csv","r")asinfile:...data=[line.strip().split(",")forlineininfile]...>>>data=data[1:]>>>defprint_data(rows):...print"".join("".join("{:<16}".format(s)forsinrow)forrowinrows)...>>>print_data(data)youngmyopenoreducednoneyoungmyopenonormalsoftyoungmyopeyesreducednoneyoungmyopeyesnormalhardyounghypermetropenoreducednoneyounghypermetropenonormalsoftyounghypermetropeyesreducednoneyounghypermetropeyesnormalhardpre-presbyopicmyopenoreducednonepre-presbyopicmyopenonormalsoftpre-presbyopicmyopeyesreducednonepre-presbyopicmyopeyesnormalhardpre-presbyopichypermetropenoreducednonepre-presbyopichypermetropenonormalsoftpre-presbyopichypermetropeyesreducednonepre-presbyopichypermetropeyesnormalnonepresbyopicmyopenoreducednonepresbyopicmyopenonormalnonepresbyopicmyopeyesreducednonepresbyopicmyopeyesnormalhardpresbyopichypermetropenoreducednonepresbyopichypermetropenonormalsoftpresbyopichypermetropeyesreducednonepresbyopichypermetropeyesnormalnone>>>data.sort(key=itemgetter(-1))>>>forvalue,groupinitertools.groupby(data,lambdar:r[-1]):...print"-----------"...print"Group:"+value...print_data(group)...-----------Group:hardyoungmyopeyesnormalhardyounghypermetropeyesnormalhardpre-presbyopicmyopeyesnormalhardpresbyopicmyopeyesnormalhard-----------Group:noneyoungmyopenoreducednoneyoungmyopeyesreducednoneyounghypermetropenoreducednoneyounghypermetropeyesreducednonepre-presbyopicmyopenoreducednonepre-presbyopicmyopeyesreducednonepre-presbyopichypermetropenoreducednonepre-presbyopichypermetropeyesreducednonepre-presbyopichypermetropeyesnormalnonepresbyopicmyopenoreducednonepresbyopicmyopenonormalnonepresbyopicmyopeyesreducednonepresbyopichypermetropenoreducednonepresbyopichypermetropeyesreducednonepresbyopichypermetropeyesnormalnone-----------Group:softyoungmyopenonormalsoftyounghypermetropenonormalsoftpre-presbyopicmyopenonormalsoftpre-presbyopichypermetropenonormalsoftpresbyopichypermetropenonormalsoft

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