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文章来自《Python cookbook》. 

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-- 61.182.251.99 [[[DateTime(2004-09-24T03:03:25Z)]]]
[[TableOfContents]]
= 描述 =
Sending Binary Data to Standard Output Under Windows

输出2进制数据到Windows标准输出上

Credit: Hamish Lawson

== 问题 Problem ==
You want to send binary data (e.g., an image) to stdout, under Windows
在windows中输出2进制数据(例如图象文件)到标准输出，

== 解决 Solution ==
That's what the setmode function, in the platform-dependent msvcrt module in Python's standard library, is for: 

Python标准库中平台相关的'''msvcrt'''模块有函数'''setmode'''，正可以解决这个任务：

{{{
#!python 
import sys

if sys.platform == "win32":
    import os, msvcrt
    msvcrt.setmode(sys.stdout.fileno(  ), os.O_BINARY)

}}}
== 讨论 Discussion ==

If you are reading or writing binary data, such as an image, under Windows, the file must be opened in binary mode (Unix doesn't make a distinction between text and binary modes). However, this is a problem for programs that write binary data to standard output (as a CGI program could be expected to do), because Python opens the sys.stdout file object on your behalf, normally in text mode. 

在Windows中读写一个2进制文件，比如图象文件，必须使用2进制模式('''rb'''参数)打开文件(Unix不区分2进制和文本文件).
然而,如果需要将2进制数据输出到标准输出(例如,CGI程序)，由于Python打开sys.stdout文件对象时默认使用了文本模式
，这样会产生问题。

You can have stdout opened in binary mode instead by supplying the -u command-line option to the Python interpreter. However, if you want to control this mode from within a program, you can use the setmode function provided by the Windows-specific msvcrt module to change the mode of stdout's underlying file descriptor, as shown in the recipe. 

启动Python解释器时使用命令行参数-u可以解决这个问题，以2进制模式打开stdout. 如果要在程序中控制输出模式, 可以如上面脚本那样使用Windows系统下特有的Python模块'''msvcrt'''中的'''setmode'''函数。 

== 参考 See Also ==
Documentation for the msvcrt module in the Library Reference.