Python使用shelve模块实现简单数据存储的方法

本文实例讲述了Python使用shelve模块实现简单数据存储的方法。分享给大家供大家参考。具体分析如下：

Python的shelve模块提供了一种简单的数据存储方案，以dict（字典）的形式来操作数据。

    #!/usr/bin/python
    import sys, shelve
    def store_person(db):
      """
      Query user for data and store it in the shelf object
      """
      pid = raw_input('Enter unique ID number:')
      person = {}
      person['name'] = raw_input('Enter name:')
      person['age'] = raw_input('Enter age:')
      person['phone'] = raw_input('Enter phone number:')
      db[pid] = person
    def lookup_person(db):
      """
      Query user for ID and desired field, 
      and fetch the corresponding data 
      from the shelf object
      """
      pid = raw_input('Enter unique ID number:')
      temp = db[pid]
      field = raw_input('Please enter name, age or phone:')
      field.strip().lower()
      print field.capitalize() + ': ', temp[field]
    def print_help():
      print 'The avaliable commands are:'
      print 'store  :Stores infomation about a person'
      print 'lookup  :Looks up a person form ID number'
      print 'quit   :Save changes and exit'
      print '?    :Prints this message'
    def enter_command():
      cmd = raw_input('Enter command(? for help):')
      cmd = cmd.strip().lower()
      return cmd
    def main():
      database = shelve.open('database')
      # database stores in current directory
      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()
        # Close database in any condition
    if __name__ == '__main__':
      main()

希望本文所述对大家的Python程序设计有所帮助。