This fixes the problem

import os import sys import termios import fcntl

    self.fd = sys.stdin.fileno()

    # Stop resetting the arduino on serial connect

    self.newattr = termios.tcgetattr(self.fd)
    self.newattr[2] = self.newattr[2] & ~termios.HUPCL
    termios.tcsetattr(self.fd, termios.TCSANOW, self.newattr)

This fixes the problem

import os
import sys
import termios
import fcntl

        self.fd = sys.stdin.fileno()

        # Stop resetting the arduino on serial connect

        self.newattr = termios.tcgetattr(self.fd)
        self.newattr[2] = self.newattr[2] & ~termios.HUPCL
        termios.tcsetattr(self.fd, termios.TCSANOW, self.newattr)