python使用marshal模块序列化实例

yipeiwu_com7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

Python3.4 tkinter,PIL图片转换

Python3.4 tkinter,PIL图片转换

先给大家分享一下全部代码 import os from PIL import Image import tkinter import tkinter.filedialog impor...

Python实现微信中找回好友、群聊用户撤回的消息功能示例

本文实例讲述了Python实现微信中找回好友、群聊用户撤回的消息功能。分享给大家供大家参考,具体如下: 还在好奇好友撤回了什么消息吗?群里撤回了什么消息?下面的代码实现了:即使群、好友撤...

python获取txt文件词向量过程详解

在读取https://github.com/Embedding/Chinese-Word-Vectors中的中文词向量时,选择了一个有3G多的txt文件,之前在做词向量时用的是word2...

利用python程序生成word和PDF文档的方法

一、程序导出word文档的方法 将web/html内容导出为world文档,再java中有很多解决方案,比如使用Jacob、Apache POI、Java2Word、iText等各种方式...

python画柱状图--不同颜色并显示数值的方法

python画柱状图--不同颜色并显示数值的方法

用python画柱状图容易,但是如何对不同柱子使用不同颜色呢?同时在柱子顶端显示精确数值? 主要用的方法为: atplotlib.pyplot.bar(left, height, wid...