Python uses the Marshal module to serialize the instance _python

This article describes the Python use of Marshal module serialization method, share for everyone to reference. The specific methods are as follows:

Let's take a look at the following code:

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, note: file must be opened in binary mode
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# give the comrades the results to see print
data2 print data3


outstring = marshal.dumps (data1) #marshal. Dumps () returns a byte string that is used to write to the file
open (' OUT.txt ', ' WB '). Write ( outstring)

file_data = open (' OUT.txt ', ' RB '). Read ()
real_data = Marshal.loads (file_data)
print Real_ Data

Results:

[' abc ', ' jb51 ']
{1: ' aaa ', ' B ': ' Dad '}
(1, 2, 4)
[' abc ', ' Jb51 ']

Several functions of the Marshel module are officially described as follows:

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 a 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 so has) a unsupported type, a ValueError exception is raised-but garbage data Would also be written to the file. The object is not is properly read back by load ().
The New in version 2.4:the version argument indicates the data format of this dump should use.
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 Eofe Rror, ValueError or TypeError. The file must be a open file object opened in binary mode (' RB ' or ' r+b ').
Warning
If an object containing an unsupported type is marshalled with dump (), load () would substitute None for the unmarshallable Type.
Marshal.dumps (value[, Version])
Return the string that would is 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 so has) an unsupported type.
The New in version 2.4:the version argument indicates the "data format" dumps should use (.
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.

use of marshal.version :Marshal does not guarantee compatibility between different versions of Python, so the function of preserving version information.

I hope this article will help you with your study of Python programming.