Simple book reader for reading text files using espeak

bookreader.py

import os
import sys
import time
import configparser
from threading import Thread

ALIVE = True  # SOFTWARE IS RUNNING
SPEAKING = True  # IS It speaking

book = sys.argv[1]
try:
    CURRENT = int(sys.argv[2])  # CURRENT LOCATION or Start from
except IndexError:
    CURRENT = 0

# Only simple stuff
valid = 'abcdefghijklmnopqrstuvwxyz'
valid += valid.upper()
valid += '0123456789., '

def getch():
    import termios
    import sys, tty
    def _getch():
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(fd)
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch

    return _getch

def listen():
    global CURRENT, ALIVE, SPEAKING
    get = getch()
    while ALIVE:
        char = get()
        if char == ' ':
            SPEAKING = not SPEAKING
            print(">" if SPEAKING else "||")
        if char == 's':
            print(CURRENT)
        if char == 'q':
            print(CURRENT)
            ALIVE = False
    print('Stopped taking input. Waiting for current sentence to complete.')


def read():
    global CURRENT, ALIVE, SPEAKING, valid
    with open(book, 'r') as fl:
        for count, raw_line in enumerate(fl.readlines()):
            if not ALIVE:
                break
            line = ''.join((i for i in raw_line.strip() if i in valid))
            if line.strip() == '':
                continue
            if count < CURRENT:
                continue
            CURRENT = count
            if SPEAKING:
                command = 'echo {}|espeak --stdin'.format(line)
                os.system(command)
            else:
                while not SPEAKING:
                    time.sleep(0.2)
    print('Closed book')



t = Thread(target=listen)
t.start()
read()