python可分组字典
# -*- encoding: UTF-8 -*- from collections import defaultdict class News(object): def __init__(self, title, type): self.title =title self.type = type def __repr__(self): return "{'title':'%s', 'type':%s}"%(self.title, self.type) newses = [ News(u"宏观研究", 1), News(u"策略报告", 1), News(u"行业研究", 2), News(u"公司研究", 3), News(u"海外资讯", 3), News(u"其他", 1) ] #print newses #{ # 1: [{'title':宏观研究, 'type':1}, {'title':策略报告, 'type':1}, {'title':其他, 'type':1}], # 2: [{'title':行业研究, 'type':2}], # 3: [{'title':公司研究, 'type':3}, {'title':海外资讯, 'type':3}] #} #方法一 d = {} for n in newses: if n.type not in d: d[n.type] = [] d[n.type].append(n) #print d #方法二 d = {} for n in newses: d.setdefault(n.type, []).append(n) #print d #方法三 d = defaultdict(list) for n in newses: d[n.type].append(n) #print d #方法四 d = defaultdict(list) map(lambda n:d[n.type].append(n),newses) #print d #方法五 d = defaultdict(list) [d[n.type].append(n) for n in newses] #print d #输出 for key in d: print key, d[key] print '==============' for key in d: for value in d[key]: print key, value print '=============='