python pickle模块

import pickle

dic = {
    1001:{
        'name': 'Alex',
        'sex': 'male',
        'balance': 1000,
        'bank_acc':{
            'ICBC': 10001,
            'ABC': 10002
        }
    },
    1002: {
        'name': 'Ken',
        'sex': 'male',
        'balance': 8000,
        'bank_acc': {
            'ICBC': 10011,
            'ABC': 10012
        }
    }
}
#存储信息
f = open('mesg.db','wb')
f.write(pickle.dumps(dic))
f.close()
#读取信息
f1 = open('mesg.db','rb')
dic = pickle.loads(f1.read())
f1.close()
#修改内容
dic[1001]['balance'] -= 600
dic[1002]['balance'] -= 1000
#重新写入
f2 = open('mesg.db','wb')
f2.write(pickle.dumps(dic))
f2.close()
#读取检查
ff = open('mesg.db','rb')
print(pickle.loads(ff.read()))
ff.close()

#{1001: {'name': 'Alex', 'sex': 'male', 'balance': 400, 'bank_acc': {'ICBC': 10001, 'ABC': 10002}},
# 1002: {'name': 'Ken', 'sex': 'male', 'balance': 7000, 'bank_acc': {'ICBC': 10011, 'ABC': 10012}}}