Python 在Linux上使用pexpect从管道读取数据

我发布了一个与get from队列相关的新问题。这是代码（感谢Martijn Pieters）

要发送到管道，我使用以下代码：

import pexpect


test = r"/home/host/PycharmProjects/Tim/Tim.py"
process = pexpect.spawn("python3 " + test)
message = '{"header":{"protocolVersion":1,"messageID":2,"stationID":400},"cam":{"generationDeltaTime":1,"camParameters":{"basicContainer":{"stationType":5}}';
process.write(message + "\n")
process.wait()

但是我如何创建一个脚本来读而不是写呢？ 我试过了

test = r"/home/host/PycharmProjects/Tim/Tim.py"
p = pexpect.spawn("python3 " + test, timeout=None)
while True:
    m = p.read()
    file = open(r"/home/host/Desktop/OpeListening.txt", "a")
    file.write(str(m))
    file.close()
p.wait()

---

但是读取会立即进入下一步，而不会显示任何消息。我的错误是什么

现在我用success Popen

process = subprocess.Popen(['python3', test], shell=False, stdout=subprocess.PIPE,
                           stdin=subprocess.PIPE, stderr=subprocess.STDOUT)
while True:
    result = process.stdout.readline()
    result = result.decode("utf-8")
    print(result)
proc.wait()

process = subprocess.Popen(['python3', test], shell=False, stdout=subprocess.PIPE,
                           stdin=subprocess.PIPE, stderr=subprocess.STDOUT)
while True:
    result = process.stdout.readline()
    result = result.decode("utf-8")
    print(result)
proc.wait()