如何在 Python 2 中将字符串传递到 subprocess.Popen 中？

发布于 2024-08-04 11:56:05 字数 934 浏览 7 评论 0原文

我想使用 Popen 从 Python (2.4/2.5/2.6) 运行一个进程，并且我想要给它一个字符串作为它的标准输入。

我将编写一个示例，其中进程执行“head -n 1”其输入。

以下有效，但我想以更好的方式解决它，而不使用 echo：

>>> from subprocess import *
>>> p1 = Popen(["echo", "first line\nsecond line"], stdout=PIPE)
>>> Popen(["head", "-n", "1"], stdin=p1.stdout)
first line

我尝试使用StringIO，但它不起作用：

>>> from StringIO import StringIO
>>> Popen(["head", "-n", "1"], stdin=StringIO("first line\nsecond line"))
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "/usr/lib/python2.4/subprocess.py", line 533, in __init__
    (p2cread, p2cwrite,
  File "/usr/lib/python2.4/subprocess.py", line 830, in _get_handles
    p2cread = stdin.fileno()
AttributeError: StringIO instance has no attribute 'fileno'

我想我可以创建一个临时文件并在那里写入字符串 - 但这也不是很好。

原文

I would like to run a process from Python (2.4/2.5/2.6) using Popen, and I
would like to give it a string as its standard input.

I'll write an example where the process does a "head -n 1" its input.

The following works, but I would like to solve it in a nicer way, without using
echo:

>>> from subprocess import *
>>> p1 = Popen(["echo", "first line\nsecond line"], stdout=PIPE)
>>> Popen(["head", "-n", "1"], stdin=p1.stdout)
first line

I tried to use StringIO, but it does not work:

>>> from StringIO import StringIO
>>> Popen(["head", "-n", "1"], stdin=StringIO("first line\nsecond line"))
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "/usr/lib/python2.4/subprocess.py", line 533, in __init__
    (p2cread, p2cwrite,
  File "/usr/lib/python2.4/subprocess.py", line 830, in _get_handles
    p2cread = stdin.fileno()
AttributeError: StringIO instance has no attribute 'fileno'

I guess I could make a temporary file and write the string there -- but that's not very nice either.

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

梦里南柯 2024-08-11 11:56:05

您是否尝试过将字符串作为字符串提供给 communicate ？

Popen.communicate(input=my_input)

它的工作原理如下：

p = subprocess.Popen(["head", "-n", "1"], stdin=subprocess.PIPE)
p.communicate('first\nsecond')

输出：

first

当我第一次尝试时，我忘记将 stdin 设置为 subprocess.PIPE。

Have you tried to feed your string to communicate as a string?

Popen.communicate(input=my_input)

It works like this:

p = subprocess.Popen(["head", "-n", "1"], stdin=subprocess.PIPE)
p.communicate('first\nsecond')

output:

first

I forgot to set stdin to subprocess.PIPE when I tried it at first.

回复收藏 0 原文

巾帼英雄 2024-08-11 11:56:05

使用 os.pipe：

>>> from subprocess import Popen
>>> import os, sys
>>> read, write = os.pipe()
>>> p = Popen(["head", "-n", "1"], stdin=read, stdout=sys.stdout)
>>> byteswritten = os.write(write, "foo bar\n")
foo bar
>>>

Use os.pipe:

>>> from subprocess import Popen
>>> import os, sys
>>> read, write = os.pipe()
>>> p = Popen(["head", "-n", "1"], stdin=read, stdout=sys.stdout)
>>> byteswritten = os.write(write, "foo bar\n")
foo bar
>>>

回复收藏 0 原文

~没有更多了~