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

ansible作为python模块库使用的方法实例

前言 ansible是新出现的自动化运维工具,基于Python开发,集合了众多运维工具(puppet、cfengine、chef、func、fabric)的优点,实现了批量系统配置、批量...

python argparser的具体使用

一.正常运行: 咱们随便写个文件: # test.py import argparse ap = argparse.ArgumentParser() ap.add_argumen...

深入分析python中整型不会溢出问题

本次分析基于 CPython 解释器,python3.x版本 在python2时代,整型有 int 类型和 long 长整型,长整型不存在溢出问题,即可以存放任意大小的整数。在pytho...

浅析PyTorch中nn.Module的使用

torch.nn.Modules 相当于是对网络某种层的封装,包括网络结构以及网络参数和一些操作 torch.nn.Module 是所有神经网络单元的基类 查看源码 初始化部分:...

为什么选择python编程语言入门黑客攻防 给你几个理由!

为什么选择python编程语言入门黑客攻防 给你几个理由!

如果选择一门编程语言来入门黑客攻防的话,你觉得哪个最合适?不如来试试Python,或许会是一次很好的尝试哦~ Python 语言的优点 目前,Python 在各领域都有着广泛的应用。由此...