from time import *
import subprocess

# 打开程序第一个参数是一个列表（程序名称，参数)
# 第二个参数是缓冲区大小
# stdin,stdout是设置是否打开这些管道，如果他的值是subprocess.PIPE的话，
# 就会打开,同stdin一样的还有stderr
child = subprocess.Popen(["python","in.py"], bufsize=1024, stdin=subprocess.PIPE, 
stdout=subprocess.PIPE)

i = 0
while True:
  if i > 10:
    break
  else:
    i += 1
    child.stdin.write(str(i).encode())
    child.stdin.write(b"\n")
    child.stdin.write(str(i+1).encode())
    child.stdin.write(b"\n")
    child.stdin.flush()
    fb = child.stdout.readline()
    print(fb.decode().strip())
    sleep(1)

child.kill()