python3与子进程通讯，怎么传输值


app.py:

import subprocess

p = subprocess.Popen("test2.exe", stdin = subprocess.PIPE,stdout = subprocess.PIPE, stderr = subprocess.PIPE, shell = False)   
p.stdin.write("3\n")   
p.stdin.write("4\n")   
print(p.stdout.read())

下面是test2.exe是用C++语言编写的：

#include <iostream>
using namespace std;

int main(int argc, const char *artv[])
{
int x, y;
cout << "input x:"<< endl;
cin >> x;
cout << "input y:"<< endl;
cin >> y;
cout << x << " + " << y << " = " << x + y << endl;

return 0;
}

[解决办法]
传参就简单了，你把第一个参数写成列表即可
就是"test2.exe" 写成 ["test2.exe", '3', '4']
[解决办法]
认真看报错信息，说不能用str，你改用bytes试试，或者用str的话Popen(..., universal_newlines=True)
p.stdin.write(b"3\n")
p.stdin.write(b"4\n")