py基于shelve模块创建插入/查看数据库应用程序

本博文源于python基础，旨在对shelve模块进行简单的学习。shelve可以将数据存储到文件，特别精巧与大家一起分享。

实验效果

这里面包含了，退出数据库，打开帮助，向数据库插入数据，查看数据库特定信息。

实验代码

实验的核心在哪里？在用shelve打开文件，之后的操作比较普通，利用字典将每个信息接受，然后甩进打开文件的句柄中去。用句柄将数据取出来即可。大家看到的友好效果就是提示效果。

import sys,shelve

def store_person(db):
    pid = input('Enter unique ID number: ')
    person = {}
    person['name'] = input('Enter name:')
    person['age'] = input('Enter age:')
    person['phone'] = input('Enter phone number:')
    db[pid] = person

def lookup_person(db):
    pid = input('Enter ID number:')
    field = input('What would you like to know?(name,age,phone)')
    field = field.strip().lower()

    print(field.capitalize() + ':',db[pid][field])

def print_help():
    print('The available commands are:')
    print('store: Stores information about a person')
    print('lookup: Looks up a person from ID number')
    print('quit: Save changes and exit')
    print('? : Prints this message')

def enter_command():
    cmd = input('Enter command(? for help):')
    cmd = cmd.strip().lower()
    return cmd

def main():
    database = shelve.open('E:\\database.dat')
    try:
        while True:
            cmd = enter_command()
            if cmd == 'store':
                store_person(database)
            elif cmd == 'lookup':
                lookup_person(database)
            elif cmd == '?':
                print_help()
            elif cmd =='quit':
                return
    finally:
        database.close()

if __name__ == '__main__':
    main()