您不需要在示例中使用process.communicate。在

只需使用process.stdin.write和process.stdout.read进行读写。还要确保发送一个新行，否则read不会返回。当您从stdin读取时，还必须处理来自echo的新行。在

注意：process.stdout.read将阻塞，直到EOF。在# talk_with_example_input.py

import subprocess

process = subprocess.Popen(["./exampleInput.sh"],

stdin = subprocess.PIPE,

stdout = subprocess.PIPE)

process.stdin.write("5\n")

stdout = process.stdout.readline()

print(stdout)

if stdout == "25\n":

process.stdin.write("yes\n")

print(process.stdout.readline())

^{pr2}$

更新

以这种方式与程序通信时，必须特别注意应用程序实际编写的内容。最好是在十六进制编辑器中分析输出：$ chimera nogui 2>&1 | hexdump -C

请注意，readline[1]只读取下一个换行符(\n)。在您的例子中，您必须至少调用readline四次才能得到第一块输出。在

如果您只想在子进程停止打印之前读取所有内容，则必须逐字节读取并实现超时。遗憾的是，read和{}都没有提供这种超时机制。这可能是因为底层的readsyscall[2](Linux)也没有提供一个。在

在Linux上，我们可以使用poll / select编写单线程read_with_timeout()。有关示例，请参见[3]。在from select import epoll, EPOLLIN

def read_with_timeout(fd, timeout__s):

"""Reads from fd until there is no new data for at least timeout__s seconds.

This only works on linux > 2.5.44.

"""

buf = []

e = epoll()

e.register(fd, EPOLLIN)

while True:

ret = e.poll(timeout__s)

if not ret or ret[0][1] is not EPOLLIN:

break

buf.append(

fd.read(1)

)

return ''.join(buf)

如果您需要一种可靠的方法来读取Windows和Linux下的非阻塞，this answer might be helpful。在readline(limit=-1)

Read and return one line from the stream. If limit is specified, at most limit bytes will be read.

The line terminator is always b'\n' for binary files; for text files, the newline argument to open() can be used to select the line terminator(s) recognized.

[2]来自man 2 read：#include

ssize_t read(int fd, void *buf, size_t count);

[3]示例$ tree

.

├── prog.py

└── prog.sh

在程序sh在#!/usr/bin/env bash

for i in $(seq 3); do

echo "${RANDOM}"

sleep 1

done

sleep 3

echo "${RANDOM}"

在进度计划在# talk_with_example_input.py

import subprocess

from select import epoll, EPOLLIN

def read_with_timeout(fd, timeout__s):

"""Reads from f until there is no new data for at least timeout__s seconds.

This only works on linux > 2.5.44.

"""

buf = []

e = epoll()

e.register(fd, EPOLLIN)

while True:

ret = e.poll(timeout__s)

if not ret or ret[0][1] is not EPOLLIN:

break

buf.append(

fd.read(1)

)

return ''.join(buf)

process = subprocess.Popen(

["./prog.sh"],

stdin = subprocess.PIPE,

stdout = subprocess.PIPE

)

print(read_with_timeout(process.stdout, 1.5))

print(' -')

print(read_with_timeout(process.stdout, 3))$ python2 prog.py

6194

14508

11293

-

10506