KeyboardInterrupt handling is extremely slow. Where is the problem? - paramiko

Question

I'm currently trying to write a script to read a shell via paramiko and, by far, if I prompt a single command it works great.
the problem is that my actual goal is to handle a debug flow and of course I cannot use a timeout because the script should listen without time limitations.
So the other option is to let the user stop the flow with ctrl-c. I added a "try, except" handler like
except (IOError, SystemExit):
raise
except KeyboardInterrupt:
print ("Crtl+C Pressed. Shutting down.")
and it seemed like it wasn't working: nothing happened when pressing ctrl-c. But then I realized that it was just taking forever: after a few minutes the script actually stops and the message appears.
Does anyone know how to handle this problem?
just for the reference here's my code
import paramiko
import time
import re
import socket
import os
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
address = '192.168.1.1'
username = 'admin'
password = ''
ssh.connect(address, port=22, username = username, password = password)
shell = ssh.invoke_shell(height=400)
shell.settimeout(2)
def prompt_console(command = '', channel = shell, timeout = False):
print(channel.recv(9999).decode('utf-8')) #<-- this is for removing the initial prompt from buffer
if timeout == False:
shell.settimeout(3600) #<--increasing the timeout
channel.send(command+'\n')
log = ''
while True:
try:
log += channel.recv(1).decode('utf-8') #<--every loop it loads a char into the "log" variable
if log[-9:] == '--More-- ':
shell.send(" ")
log.replace('--More-- \r \r\t\t','\r\t\t')
if len(re.findall('.*\n',log))>0: #<--it yields every line to python console
yield log
log = ''
except (IOError, SystemExit):
raise
except KeyboardInterrupt:
print ("Crtl+C Pressed. Shutting down.")
I also tried to put the try-except outside the while loop but it didn't work. I also tried many suggestions that I've found on google but they didn't work either: they all stop the script eventually but for all of them it takes 5-10 minutes.