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?

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。

Popen.communicate()的文档:

请注意，如果要将数据发送到 这个过程是标准的，你需要 创建Popen对象 stdin =管。同样，要得到任何东西 除了结果元组中的None， 你需要给stdout=PIPE和/或 stderr =管。 取代os.popen *

    pipe = os.popen(cmd, 'w', bufsize)
    # ==>
    pipe = Popen(cmd, shell=True, bufsize=bufsize, stdin=PIPE).stdin

警告使用communication()代替 Stdin.write ()， stdout.read()或 Stderr.read()避免死锁 到任何其他操作系统管道缓冲区 填充和阻塞孩子 的过程。

所以你的例子可以写成这样:

from subprocess import Popen, PIPE, STDOUT

p = Popen(['grep', 'f'], stdout=PIPE, stdin=PIPE, stderr=STDOUT)    
grep_stdout = p.communicate(input=b'one\ntwo\nthree\nfour\nfive\nsix\n')[0]
print(grep_stdout.decode())
# -> four
# -> five
# ->

在Python 3.5+(编码为3.6+)上，你可以使用subprocess.run，将输入作为字符串传递给外部命令，并在一次调用中获得其退出状态和输出作为字符串返回:

#!/usr/bin/env python3
from subprocess import run, PIPE

p = run(['grep', 'f'], stdout=PIPE,
        input='one\ntwo\nthree\nfour\nfive\nsix\n', encoding='ascii')
print(p.returncode)
# -> 0
print(p.stdout)
# -> four
# -> five
# -> 

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)

from subprocess import Popen, PIPE
from tempfile import SpooledTemporaryFile as tempfile
f = tempfile()
f.write('one\ntwo\nthree\nfour\nfive\nsix\n')
f.seek(0)
print Popen(['/bin/grep','f'],stdout=PIPE,stdin=f).stdout.read()
f.close()

"""
Ex: Dialog (2-way) with a Popen()
"""

p = subprocess.Popen('Your Command Here',
                 stdout=subprocess.PIPE,
                 stderr=subprocess.STDOUT,
                 stdin=PIPE,
                 shell=True,
                 bufsize=0)
p.stdin.write('START\n')
out = p.stdout.readline()
while out:
  line = out
  line = line.rstrip("\n")

  if "WHATEVER1" in line:
      pr = 1
      p.stdin.write('DO 1\n')
      out = p.stdout.readline()
      continue

  if "WHATEVER2" in line:
      pr = 2
      p.stdin.write('DO 2\n')
      out = p.stdout.readline()
      continue
"""
..........
"""

out = p.stdout.readline()

p.wait()

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

我使用python3，发现你需要编码你的字符串，然后才能将它传递到stdin:

p = Popen(['grep', 'f'], stdout=PIPE, stdin=PIPE, stderr=PIPE)
out, err = p.communicate(input='one\ntwo\nthree\nfour\nfive\nsix\n'.encode())
print(out)

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)

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,
)

在Python 3.7+上这样做:

my_data = "whatever you want\nshould match this f"
subprocess.run(["grep", "f"], text=True, input=my_data)

并且您可能希望添加capture_output=True以获得以字符串形式运行命令的输出。

在旧版本的Python中，将text=True替换为universal_newlines=True:

subprocess.run(["grep", "f"], universal_newlines=True, input=my_data)

这对于grep来说有点过分了，但是通过我的学习，我已经了解了Linux命令expect和python库pexpect

期望:对话与互动程序 pexpect:用于生成子应用程序的Python模块;控制他们;并在他们的输出中响应预期的模式。

import pexpect
child = pexpect.spawn('grep f', timeout=10)
child.sendline('text to match')
print(child.before)

使用pexpect使用交互式shell应用程序(如ftp)非常简单

import pexpect
child = pexpect.spawn ('ftp ftp.openbsd.org')
child.expect ('Name .*: ')
child.sendline ('anonymous')
child.expect ('Password:')
child.sendline ('noah@example.com')
child.expect ('ftp> ')
child.sendline ('ls /pub/OpenBSD/')
child.expect ('ftp> ')
print child.before   # Print the result of the ls command.
child.interact()     # Give control of the child to the user.