Remote control bash from Python

bash_.py

from subprocess import Popen, PIPE
from sys import argv
import re

stop = "qwertz1234567890ufugUUGUGUgUgUGuGFzR775§%!=%%54321rUF/Rtt8t8TTT4§2hj\n"
bye  = ["tschüs","do_widzenia","ahoj","ciao","salut","adieu","vaarwel","farvel"]
byes = re.sub(r"['[]]*", "", str(bye))

cmd = "bash" if len(argv) == 1 else argv[1]

p = Popen(cmd, stdin=PIPE, stdout=PIPE)

while True:
    i = input(cmd + ": ")
    if i in bye:  break
    if i == "?":
        print("'cmd' gets executed\n'?' for this help\nto exit, any of: "+byes)
        continue

    p.stdin.write(bytes(i + "\necho " + stop, 'utf-8'));  p.stdin.flush()

    while True:
        resp = p.stdout.readline().decode(encoding="utf-8")
        if resp == stop:  break

        print(resp, end="")

If responses are known to be 1 line always, much simpler bash1.py can be used:
https://gist.github.com/Hermann-SW/4c5b204f2eecf712b568bf85ee111a2b