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

python正则实现提取电话功能

本文实例为大家分享了python正则提取电话的具体代码,供大家参考,具体内容如下 主要用到正则 import re import xlrd def is_number(s):#是...

通过celery异步处理一个查询任务的完整代码

今天介绍通过celery实现一个异步任务。有这样一个需求,前端发起一个查询的请求,但是发起查询后,查询可能不会立即返回结果。这时候,发起查询后,后端可以把这次查询当作一个task,并立即...

8段用于数据清洗Python代码(小结)

最近,大数据工程师Kin Lim Lee在Medium上发表了一篇文章,介绍了8个用于数据清洗的Python代码。 数据清洗,是进行数据分析和使用数据训练模型的必经之路,也是最耗费数据科...

Django生成PDF文档显示在网页上以及解决PDF中文显示乱码的问题

Django生成PDF文档显示在网页上以及解决PDF中文显示乱码的问题

项目地址:https://github.com/PythonerKK/django-generate-pdf/tree/master 这个demo实现了通过用户输入自己的个人信息生成一份...

Python中的 ansible 动态Inventory 脚本

Python中的 ansible 动态Inventory 脚本

1.Ansible Inventory  介绍; Ansible Inventory 是包含静态 Inventory 和动态 Inventory 两部分的,静态 Invento...