python调用exe文件并向其中输入参数（多用于批处理）

import os
import subprocess

rootdir=os.path.join('D:SPI1')#修改自己的路径

for (dirpath,dirnames,filenames) in os.walk(rootdir):
    for filename in filenames:
        if os.path.splitext(filename)[1]=='.txt':
            # write_path.write('要写的绝对路径'+filename+'n')
            proc = subprocess.Popen('SPI_SL_6.exe', stdin=subprocess.PIPE)
            proc.stdin.write(b"3n")
            proc.stdin.write(b"1n")
            proc.stdin.write(b"3n")
            proc.stdin.write(b"12n")
            proc.stdin.write(b"SP1/"+filename.encode()+b"n")#修改自己的路径
            proc.stdin.write(b"SP2/"+filename.encode()+b"n")#修改自己的路径
            proc.stdin.flush()
            proc.stdin.close()