• 序列化模块


    # 模块: 一个py文件就是一个模块.
    '''
        python开发效率之高:Python的模块非常多,第三方库.
        模块分类:
            1,内置模块:登录模块,时间模块,sys模块,os模块 等等.
            2,扩展模块. itchat 微信有关.爬虫: beautifulsoup
                所有的扩展模块:https://pypi.org/
            3,自定义模块.自己写的py文件.
    
    '''
    # 序列化模块.
    #序列化:创造一个序列.
    #实例化:创造一个实例(对象).
    # 将一个字典通过网络传输给另一个人.
    '''
    文件中可以存储:字符串,和bytes.
    数据的传输:bytes类型.
    '''
    #  序列化: 创造一个序列, ---> 特殊处理(序列化的)字符串.
    
    #序列化:
            # json:
            #         适用于不同语言之间的,
            #         但是可支持的数据类型:字符串,数字,列表(元祖),字典,float,bool,None 
            # pickle:
                # 只用于python语言之间的.
                #可支持python所有的数据类型.
            # shelve(了解):只是python,小工具(文件方面).
    
    #序列化过程: 一个数据类型 ---> 序列化的字符串
    #反序列化过程: 序列化的字符串  --->  它所对应的数据类型
    # dumps  loads 网络的传输
    # dic = {"alex": ['women','women','老女人'],'p1':True}
    # dic = {"alex": ('women','women','老女人')}
    # print(str(dic))  # 基础数据类型str  里面如果有引号就是单引号
    # ret = json.dumps(dic,ensure_ascii=False) # 序列化过程:数据类型dic---> 序列化的字符串
    # print(ret,type(ret))
    # 被json序列化的字符串:
    #1,可以直接通过网络互相传输.
    #2,可以在各个语言中通用.
    # dic1 = json.loads(ret)  # 反序列化过程.:将序列化的字符串---> 原有的数据类型.
    # print(dic1,type(dic1))
    
    
    #dump  load 有关文件存储
    # import json
    # l1 = ['张三','历史','王五','alex','老土','旭哥']
    # f = open('json_file',encoding='utf-8',mode='w')
    # json.dump(l1,f,ensure_ascii=False)  # 将序列化的字符串存储到文件中
    # f.close()
    
    # f = open('json_file',encoding='utf-8')
    # ret = json.load(f)
    # print(ret,type(ret))
    # f.close()
    # 有关文件存储的问题?
    import json # dic = {"alex": ('women','women','老女人')} # dic2 = {"alex1": ('women','women','老女人')} # dic3 = {"alex2": ('women','women','老女人')} # f = open('json_files',encoding='utf-8',mode='w') # json.dump(dic,f,ensure_ascii=False) # json.dump(dic2,f,ensure_ascii=False) # json.dump(dic3,f,ensure_ascii=False) # f.close() # f = open('json_files', encoding='utf-8',) # print(json.load(f)) # print(json.load(f)) # print(json.load(f)) # f.close()
    #
    将多个序列化的字符串写入文件,然后反序列化,就会出错 # 用 dump load 只能写入和读取文件 一个序列化的字符串
    # 用dumps和loads操作
    import json
    #
    dic = {"alex": ('women','women','老女人')} # dic2 = {"alex1": ('women','women','老女人')} # dic3 = {"alex2": ('women','women','老女人')} # with open('json_files',encoding='utf-8',mode='a') as f1: # s1 = json.dumps(dic,ensure_ascii=False) # f1.write(s1+' ') # s2 = json.dumps(dic2,ensure_ascii=False) # f1.write(s2+' ') # s3 = json.dumps(dic3,ensure_ascii=False) # f1.write(s3+' ') # # with open('json_files',encoding='utf-8') as f2: # for line in f2: # dic = json.loads(line) # print(dic,type(dic))
    # 其他参数
    # import json
    # data = {'username':['李华','二愣子'],'sex':'male','age':16,'A':666}
    # json_dic2 = json.dumps(data,sort_keys=True,indent=2,separators=('|','*'),ensure_ascii=False)
    # print(json_dic2)
    #
    # print(json.loads(json_dic2)) # 如果改了:separators=('|','*')反序列化不行了
    # sort_keys=True 字典键的首字母的ascii码排序
    # ensure_ascii=False 显示中文
    # indent=2 key 缩进
    
    # dic = {(1,2,3):'alex',1:[1,2,3]}
    # ret = json.dumps(dic)
    # print(ret)  # TypeError: keys must be a string
    # dumps  loads  网络传输
    # dic = {1:True,(2,3):[1,2,3,4],False:{1,2,3}}
    # import pickle
    # ret = pickle.dumps(dic)  # bytes类型无法识别内容
    #
    # dic1 = pickle.loads(ret)
    # print(dic1,type(dic1))
    
    # dump  load 文件操作
    # dic = {1:True,(2,3):[1,2,3,4],False:{1,2,3}}
    
    # import pickle
    # with open('pickle_file',mode='wb') as f1:
    #     pickle.dump(dic,f1)
    
    # with open('pickle_file',mode='rb') as f2:
    #     print(pickle.load(f2))
    # 多个数据存储到一个文件 (dump.load)
    # dic = {"alex": ('women','women','老女人')}
    # dic2 = {"alex1": ('women','women','老女人')}
    # dic3 = {"alex2": ('women','women','老女人')}
    
    # import pickle
    # with open('pickle_files',mode='wb') as f1:
    #     pickle.dump(dic,f1)
    #     pickle.dump(dic2,f1)
    #     pickle.dump(dic3,f1)
    #     pickle.dump(dic3,f1)
    
    
    # with open('pickle_files',mode='rb') as f1:
    #     while True:
    #         try:
    #             print(pickle.load(f1))
    #         except EOFError:
    #             break
    shelve 与文件相关
    #
    import shelve # f = shelve.open('shelve_file') # f['key'] = {'int':10, 'float':9.5, 'string':'Sample data'} #直接对文件句柄操作,就可以存入数据 # f.close() # import shelve # f1 = shelve.open('shelve_file') # existing = f1['key'] #取出数据的时候也只需要直接用key获取即可,但是如果key不存在会报错 # f1.close() # print(existing)
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  • 原文地址:https://www.cnblogs.com/molieren/p/9272909.html
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