（Python基础教程之十七）Python OrderedDict –有序字典

一个OrderedDict维护插入顺序添加到字典中的项目。项目的顺序在迭代或序列化时也会保留。1. Python OrderedDict示例OrderedDict 是python collections模块的一部分。要轻松构建OrderedDict，可以OrderedDict在collections模块中使用。OrderedDictExample.py from collections import OrderedDict d = OrderedDict() d['how'] = 1 d['to'] = 2 d['do'] = 3 d['in'] = 4 d['java'] = 5 for key in d: print(key, d[key]) ('how', 1) ('to', 2) ('do', 3) ('in', 4) ('java', 5)2.将OrderedDict转换为JSON项目的顺序在序列化为JSON时也会保留。OrderedDict JSON示例from collections import OrderedDict import json d = OrderedDict() d['how'] = 1 d['to'] = 2 d['do'] = 3 d['in'] = 4 d['java'] = 5 json.dumps(d) '{"how"