json & pickle 模块

#!/usr/bin/env python# -*- coding:utf-8 -*-import jsondic = {‘k1‘:1,‘k2‘:2,‘k3‘:3}str_dic = json.dumps(dic) ?##序列化：将一个字典转换成一个字符串print(type(str_dic),str_dic) ?#<class ‘str‘> {"k1": 1, "k2": 2, "k3": 3}#注意，json转换完的字符串类型的字典中的字符串是由""表示的dic2 = json.loads(str_dic)#反序列化：将一个字符串格式的字典转换成一个字典print(dic2)#{‘k1‘: 1, ‘k2‘: 2, ‘k3‘: 3}#注意，要用json的loads功能处理的字符串类型的字典中的字符串必须由""表示list_dic = [1,[‘k1:1‘],‘a‘,‘b‘,‘c‘,[1,2,3]] #也可以处理嵌套的数据类型 str_dic = json.dumps(list_dic)print(type(list_dic),list_dic) ?#<class ‘list‘> [1, [‘k1:1‘], ‘a‘, ‘b‘, ‘c‘, [1, 2, 3]]str_dic2 = json.loads(str_dic)print(type(str_dic2),str_dic2) #<class ‘list‘> [1, [‘k1:1‘], ‘a‘, ‘b‘, ‘c‘, [1, 2, 3]]

import jsonf = open(‘json_file‘,‘w‘)dic = {‘k1‘:‘v1‘,‘k2‘:‘v2‘,‘k3‘:‘v3‘}json.dump(dic,f) ?#dump方法接收一个文件句柄，直接将字典转换成json字符串写入文件f.close()f = open(‘json_file‘)dic2 = json.load(f) ?#load方法接收一个文件句柄，直接将文件中的json字符串转换成数据结构返回f.close()print(type(dic2),dic2)load和dump

import jsonf = open(‘file‘,‘w‘)json.dump({‘国籍‘:‘中国‘},f)ret = json.dumps({‘国籍‘:‘中国‘})f.write(ret+‘\n‘)json.dump({‘国籍‘:‘美国‘},f,ensure_ascii=False)ret = json.dumps({‘国籍‘:‘美国‘},ensure_ascii=False)f.write(ret+‘\n‘)f.close()

Serialize obj to a JSON formatted str.(字符串表示的json对象) Skipkeys：默认值是False，如果dict的keys内的数据不是python的基本类型(str,unicode,int,long,float,bool,None)，设置为False时，就会报TypeError的错误。此时设置成True，则会跳过这类key ensure_ascii:，当它为True的时候，所有非ASCII码字符显示为\uXXXX序列，只需在dump时将ensure_ascii设置为False即可，此时存入json的中文即可正常显示。) If check_circular is false, then the circular reference check for container types will be skipped and a circular reference will result in an OverflowError (or worse). If allow_nan is false, then it will be a ValueError to serialize out of range float values (nan, inf, -inf) in strict compliance of the JSON specification, instead of using the JavaScript equivalents (NaN, Infinity, -Infinity). indent：应该是一个非负的整型，如果是0就是顶格分行显示，如果为空就是一行最紧凑显示，否则会换行且按照indent的数值显示前面的空白分行显示，这样打印出来的json数据也叫pretty-printed json separators：分隔符，实际上是(item_separator, dict_separator)的一个元组，默认的就是(‘,’,’:’)；这表示dictionary内keys之间用“,”隔开，而KEY和value之间用“：”隔开。 default(obj) is a function that should return a serializable version of obj or raise TypeError. The default simply raises TypeError. sort_keys：将数据根据keys的值进行排序。 To use a custom JSONEncoder subclass (e.g. one that overrides the .default() method to serialize additional types), specify it with the cls kwarg; otherwise JSONEncoder is used.

import jsondata = {‘username‘:[‘李华‘,‘二愣子‘],‘sex‘:‘male‘,‘age‘:16}json_dic2 = json.dumps(data,sort_keys=True,indent=2,separators=(‘,‘,‘:‘),ensure_ascii=False)print(json_dic2)

import pickledic = {‘k1‘:‘v1‘,‘k2‘:‘v2‘,‘k3‘:‘v3‘}str_dic = pickle.dumps(dic)print(str_dic) ?#一串二进制内容dic2 = pickle.loads(str_dic)print(dic2) ???#字典import timestruct_time ?= time.localtime(1000000000)print(struct_time)f = open(‘pickle_file‘,‘wb‘)pickle.dump(struct_time,f)f.close()f = open(‘pickle_file‘,‘rb‘)struct_time2 = pickle.load(f)print(struct_time2.tm_year)