sub process,如何利用python与苹果shell交互

考虑这样一个问题,有hello.py脚本,输出”hello, world!”sub process;有TestInput.py脚本,等待用户输入,然后打印用户输入的数据。那么,怎么样把hello.py输出内容发送给TestInput.py,最后TestInput.py打印接收到的”hello, world!”。下面我来逐步讲解一下shell的交互方式。

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sub process,如何利用python与苹果shell交互

hello.py代码如下:

#!/usr/bin/pythonprint \"hello, world!\"TestInput.py代码如下:

#!/usr/bin/pythonstr = raw_input()print(\"input string is: %s\" % str)1.os.system(cmd)

这种方式只是执行shell命令,返回一个返回码(0表示执行成功,否则表示失败)

retcode = os.system(\"python hello.py\")print(\"retcode is: %s\" % retcode);输出:

hello, world!retcode is: 02.os.popen(cmd)

执行命令并返回该执行命令程序的输入流或输出流.该命令只能操作单向流,与shell命令单向交互,不能双向交互.

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返回程序输出流,用fouput变量连接到输出流

fouput = os.popen(\"python hello.py\")result = fouput.readlines()print(\"result is: %s\" % result);

输出:

result is: [\'hello, world!\\n\']

返回输入流,用finput变量连接到输出流

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复制代码 代码如下:finput = os.popen(\"python TestInput.py\", \"w\")finput.write(\"how are you\\n\")输出:

input string is: how are you

3.利用subprocess模块

subprocess.call()

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类似os.system(),注意这里的”shell=True”表示用shell执行命令,而不是用默认的os.execvp()执行.

f = call(\"python hello.py\", shell=True)print f

输出:

hello, world!

subprocess.Popen()利用Popen可以是实现双向流的通信,可以将一个程序的输出流发送到另外一个程序的输入流. Popen()是Popen类的构造函数,communicate()返回元组(stdoutdata, stderrdata).

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p1 = Popen(\"python hello.py\", stdin = None, stdout = PIPE, shell=True)p2 = Popen(\"python TestInput.py\", stdin = p1.stdout, stdout = PIPE, shell=True)print p2.communicate()[0]#other way#print p2.stdout.readlines()

输出:

input string is: hello, world!

整合代码如下:

#!/usr/bin/pythonimport osfrom subprocess import Popen, PIPE, callretcode = os.system(\"python hello.py\")print(\"retcode is: %s\" % retcode);fouput = os.popen(\"python hello.py\")result = fouput.readlines()print(\"result is: %s\" % result);finput = os.popen(\"python TestInput.py\", \"w\")finput.write(\"how are you\\n\")f = call(\"python hello.py\", shell=True)print fp1 = Popen(\"python hello.py\", stdin = None, stdout = PIPE, shell=True)p2 = Popen(\"python TestInput.py\", stdin = p1.stdout, stdout = PIPE, shell=True)print p2.communicate()[0]#other way#print p2.stdout.readlines()

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