如何使用python子进程执行命令并响应多个输入？

Question

I am trying to understand how to execute a command/program using python subprocess module & respond to the prompt by giving input.

Sample Program Program1.py which can take multiple input's:

arr1=[]
username = input("Enter your username1 : ")
password = input("Enter your password1 : ")
arr1.append((username,password))
username = input("Enter your username2 : ")
password = input("Enter your password2 : ")
arr1.append((username,password))
username = input("Enter your username3 : ")
password = input("Enter your password3 : ")
arr1.append((username,password))
username = input("Enter your username4 : ")
password = input("Enter your password4 : ")
arr1.append((username,password))

for item in arr1:
    print("username:",item[0],"Password:",item[1])

I have written another program called Execute_Program1.py

import subprocess

proc = subprocess.Popen('python Program1.py',stdout=subprocess.PIPE,stderr=subprocess.PIPE,stdin=subprocess.PIPE,shell=True,universal_newlines=True)
print(proc.poll())
while proc.poll() is None:
    print(proc.stdout)
    proc.stdin.write('inputdata\n')

But this program is not able to execute the Program1.py. I have read many posts related to this. As per the information I have got proc.poll() return's None then the command executed by Popen is still active. But my program is giving the following output:

None
<_io.TextIOWrapper name=4 encoding='cp1252'>

I am using Python version 3.7.4. Could anyone please help me with some inputs where I am doing mistake? Thanks in advance.

Answer 1

I could not get it to work with subprocess at this time but I wanted you to have an ASAP working solution using the os module in case you need this quickly and are not absolutely required to use the subprocess module...

First add this line to the end of Program1.py, with no indentation, to prevent the command window from exiting before you have a chance to see the output:

input("Press <enter> to continue")

Next, replace your entire code in Execute_Program1.py with the following:

import os
os.system("python Program1.py 1")

This worked beautifully in Python 3.8.1 on win10pro.