python 基础之数据持久化存储

###数据持久化存储

- 说明：持久化存储方案，普通文件、数据库、序列化

- 示例：

  ```python
  import pickle

  class Person:
      def __init__(self, name, age):
          self.name = name
          self.age = age

      def __str__(self):
          return ‘name:{} age:{}‘.format(self.name, self.age)
     
     
  xiaoming = Person(‘xiaoming‘, 20)
  # print(xiaoming)

  # 序列化：会将对象转换为bytes
  # s = pickle.dumps(xiaoming)
  # print(s)

  # 反序列化：从bytes中解析出对象
  # xm = pickle.loads(s)
  # print(xm, type(xm)) 

  # 直接保存到文件
  # fp = open(‘data.txt‘, ‘wb‘)
  # pickle.dump(xiaoming, fp)
  # fp.close()

  # 从文件中读取对象
  fp = open(‘data.txt‘, ‘rb‘)
  xm = pickle.load(fp)
  print(xm, type(xm))