python使用marshal模块序列化实例

yipeiwu_com6年前Python基础

本文实例讲述了python使用marshal模块序列化的方法,分享给大家供大家参考。具体方法如下:

先来看看下面这段代码:

import marshal
data1 = ['abc',12,23,'jb51']  #几个测试数据
data2 = {1:'aaa',"b":'dad'}
data3 = (1,2,4)

output_file = open("a.txt",'wb')#把这些数据序列化到文件中,注:文件必须以二进制模式打开
marshal.dump(data1,output_file)
marshal.dump(data2,output_file)
marshal.dump(data3,output_file)
output_file.close()


input_file = open('a.txt','rb')#从文件中读取序列化的数据
#data1 = []
data1 = marshal.load(input_file)
data2 = marshal.load(input_file)
data3 = marshal.load(input_file)
print data1#给同志们打印出结果看看
print data2
print data3


outstring = marshal.dumps(data1)#marshal.dumps()返回是一个字节串,该字节串用于写入文件
open('out.txt','wb').write(outstring)

file_data = open('out.txt','rb').read()
real_data = marshal.loads(file_data)
print real_data

结果:

['abc', 12, 23, 'jb51']
{1: 'aaa', 'b': 'dad'}
(1, 2, 4)
['abc', 12, 23, 'jb51']

marshel模块的几个函数官方描述如下:

The module defines these functions:
marshal.dump(value, file[, version])
Write the value on the open file. The value must be a supported type. The file must be an open file object such as sys.stdout or returned by open() or os.popen(). It must be opened in binary mode ('wb' or 'w+b').
If the value has (or contains an object that has) an unsupported type, a ValueError exception is raised — but garbage data will also be written to the file. The object will not be properly read back by load().
New in version 2.4: The version argument indicates the data format that dump should use (see below).
marshal.load(file)
Read one value from the open file and return it. If no valid value is read (e.g. because the data has a different Python version's incompatible marshal format), raise EOFError, ValueError or TypeError. The file must be an open file object opened in binary mode ('rb' or 'r+b').
Warning
If an object containing an unsupported type was marshalled with dump(), load() will substitute None for the unmarshallable type.
marshal.dumps(value[, version])
Return the string that would be written to a file by dump(value, file). The value must be a supported type. Raise a ValueError exception if value has (or contains an object that has) an unsupported type.
New in version 2.4: The version argument indicates the data format that dumps should use (see below).
marshal.loads(string)
Convert the string to a value. If no valid value is found, raise EOFError, ValueError or TypeError. Extra characters in the string are ignored.
In addition, the following constants are defined:
marshal.version
Indicates the format that the module uses.

marshal.version的用处marshal不保证不同的python版本之间的兼容性,所以保留个版本信息的函数.

希望本文所述对大家Python程序设计的学习有所帮助。

相关文章

python list使用示例 list中找连续的数字

线上有个需求,格式化,从一堆s1,s100-s199中找出连续的服并且格式化显示出来,如:神魔:S106-109,s123,s125御剑: s106-109,s123,s125复制代码...

Python打造出适合自己的定制化Eclipse IDE

Python打造出适合自己的定制化Eclipse IDE

Eclipse是一套强大的框架,其能够通过内置插件机制实现多种扩展方式。然而要想添加一小点额外功能,大家都不可避免地需要面临新插件的编写与部署工作,这显然有点令人头痛。现在在EASE的帮...

朴素贝叶斯分类算法原理与Python实现与使用方法案例

朴素贝叶斯分类算法原理与Python实现与使用方法案例

本文实例讲述了朴素贝叶斯分类算法原理与Python实现与使用方法。分享给大家供大家参考,具体如下: 朴素贝叶斯分类算法 1、朴素贝叶斯分类算法原理 1.1、概述 贝叶斯分类算法是一大类分...

TensorFlow Session使用的两种方法小结

TensorFlow Session使用的两种方法小结

TensorFlow Session 在TensorFlow中是通过session进行交互的,使用session有两种方法。下面通过一个简单的例子(两个矩阵相乘)说一下 {[3,1] 与...

Python中最大递归深度值的探讨

Python中最大递归深度值的探讨

Python对递归函数设置是有默认值。 可以通过下面命令来查看设置的默认值 >>> import sys >>> sys.getrecursion...