二十五、python中pickle序列学习(仅python语言中有)

1.pickle序列介绍：提供4个关键字：dumps，dump，loads，load

　　语法：f.write(pickle.dumps(dict))=pickle.dump(dict,f)

　　　　　"r=pickle.loads(f.read())" = "r=pickle.load(f)

　　将字典存入文件，由于字典格式不能转化成字节格式的，所以引入pickle

　　A.将一个字典转化成pickle序列存入一个文件

import pickle
#import cPickle as pickle

accounts={
    1000:{
        'name':'Tom',
        'email':'22016311@qq.com',
        'passwd':'abc123',
        'balance':20000,
        'phone':'44165465',
        'bank_acc':{
            'ICBC':165116161,
            'CBC':16516516516,
            'ABC':656151616516
        }
    },
1001:{
        'name':'Tom1',
        'email':'220116311@qq.com',
        'passwd':'abc1123',
        'balance':210000,
        'phone':'441654165',
        'bank_acc':{
            'ICBC':16511161611,
            'CBC':165165165161,
            'ABC':6561516165161
        }
    }
}

print (pickle.dumps(accounts))   #将字典转成pickle序列
f=open("account.db","wb")        #写入文件account.db
f.write(pickle.dumps(accounts))  #写入文件account.db
#pickle.dump(accounts,f)

f.close()
-------------------------------------------------------------------
b'x80x03}qx00(Mxe8x03}qx01(Xx04x00x00x00nameqx02Xx03x00x00x00Tomqx03Xx05x00x00x00emailqx04Xx0fx00x00x0022016311@qq.comqx05Xx06x00x00x00passwdqx06Xx06x00x00x00abc123qx07Xx07x00x00x00balanceqx08M NXx05x00x00x00phoneq	Xx08x00x00x0044165465q
Xx08x00x00x00bank_accqx0b}qx0c(Xx04x00x00x00ICBCq
Jx01yxd7	Xx03x00x00x00CBCqx0ex8ax05xa4
vxd8x03Xx03x00x00x00ABCqx0fx8ax06x04x1cxafxc5x98x00uuMxe9x03}qx10(hx02Xx04x00x00x00Tom1qx11hx04Xx10x00x00x00220116311@qq.comqx12hx06Xx07x00x00x00abc1123qx13hx08JP4x03x00h	X	x00x00x00441654165qx14hx0b}qx15(h
x8ax05x0bU$xd8x03hx0ex8ax05ijx9ct&hx0fx8ax06)x18xd7xb8xf7x05uuu.'

　　B.重新创建一个新的python文件读取account.db中的内容：

import pickle

account_file=open("account.db","rb")                   #打开文件
account_dict=pickle.loads(account_file.read())         #以pickle加载文件
#account_dict=pickle.load(account_file)
#print (account_dict)
account_file.close()
#print(type(account_dict[1000]['balance']))             
account_dict[1000]['balance'] -= 500                   #取字典中balance然后减500
print (account_dict)

f=open("account.db","wb")
f.write(pickle.dumps(account_dict))                    #将变更后的内容dumps入文件
f.close()
print (account_dict)
-----------------------------------------------------------------------------

{1000: {'name': 'Tom', 'email': '22016311@qq.com', 'passwd': 'abc123', 'balance': 19500, 'phone': '44165465', 'bank_acc': {'ICBC': 165116161, 'CBC': 16516516516, 'ABC': 656151616516}}, 1001: {'name': 'Tom1', 'email': '220116311@qq.com', 'passwd': 'abc1123', 'balance': 210000, 'phone': '441654165', 'bank_acc': {'ICBC': 16511161611, 'CBC': 165165165161, 'ABC': 6561516165161}}}
{1000: {'name': 'Tom', 'email': '22016311@qq.com', 'passwd': 'abc123', 'balance': 19500, 'phone': '44165465', 'bank_acc': {'ICBC': 165116161, 'CBC': 16516516516, 'ABC': 656151616516}}, 1001: {'name': 'Tom1', 'email': '220116311@qq.com', 'passwd': 'abc1123', 'balance': 210000, 'phone': '441654165', 'bank_acc': {'ICBC': 16511161611, 'CBC': 165165165161, 'ABC': 6561516165161}}}