显然是cStringIO。StringIO对象的嘎嘎声不够接近 适合子进程的文件鸭。Popen

恐怕不行。管道是一个低级的操作系统概念，因此它绝对需要一个由操作系统级文件描述符表示的文件对象。你的解决方法是正确的。

p = Popen(['grep', 'f'], stdout=PIPE, stdin=PIPE, stderr=STDOUT)    
p.stdin.write('one\n')
time.sleep(0.5)
p.stdin.write('two\n')
time.sleep(0.5)
p.stdin.write('three\n')
time.sleep(0.5)
testresult = p.communicate()[0]
time.sleep(0.5)
print(testresult)

Beware that Popen.communicate(input=s)may give you trouble ifsis too big, because apparently the parent process will buffer it before forking the child subprocess, meaning it needs "twice as much" used memory at that point (at least according to the "under the hood" explanation and linked documentation found here). In my particular case,swas a generator that was first fully expanded and only then written tostdin so the parent process was huge right before the child was spawned, and no memory was left to fork it:

文件“/opt/local/stow/python-2.7.2/lib/python2.7/subprocess.py”，第1130行，在_execute_child中 自我。Pid = os.fork() OSError: [Errno 12]不能分配内存

我想出了一个变通办法:

>>> p = subprocess.Popen(['grep','f'],stdout=subprocess.PIPE,stdin=subprocess.PIPE)
>>> p.stdin.write(b'one\ntwo\nthree\nfour\nfive\nsix\n') #expects a bytes type object
>>> p.communicate()[0]
'four\nfive\n'
>>> p.stdin.close()

还有更好的吗?

如果您使用的是Python 3.4或更高版本，那么有一个很好的解决方案。使用input参数而不是stdin参数，它接受bytes参数:

output_bytes = subprocess.check_output(
    ["sed", "s/foo/bar/"],
    input=b"foo",
)

这适用于check_output和run，但不适用于call或check_call。

在Python 3.7+中，你还可以添加text=True，使check_output接受一个字符串作为输入并返回一个字符串(而不是字节):

output_string = subprocess.check_output(
    ["sed", "s/foo/bar/"],
    input="foo",
    text=True,
)

我有点惊讶没有人建议创建管道，在我看来，这是将字符串传递给子进程的stdin的最简单的方法:

read, write = os.pipe()
os.write(write, "stdin input here")
os.close(write)

subprocess.check_call(['your-command'], stdin=read)