Непонятно, почему выбивает?

import os
import re
from pygame import mixer
import datetime
import time
from gtts import gTTS
mp3_nameold='111'
mp3_name = "1.mp3"
mixer.init()
f = open('1.txt','r')
ss = f.readline()
while ss:
split_regex = re.compile(r'[.|!|?|…]')
sentences = filter(lambda t: t, [t.strip() for t in split_regex.split(ss)])
for x in sentences:
if(x!=""):
print(x)
tts=gTTS(text=x, lang='ru')
tts.save(mp3_name)
mixer.music.load(mp3_name)
mixer.music.play()
while mixer.music.get_busy():
time.sleep(0.1)
if(os.path.exists(mp3_nameold) and (mp3_nameold!="1.mp3")):
os.remove(mp3_nameold)
mp3_nameold=mp3_name
now_time = datetime.datetime.now()
mp3_name = now_time.strftime("%d%m%Y%I%M%S")+".mp3"
ss = f.readline()
f.close
mixer.music.load('1.mp3')
mixer.stop
mixer.quit
if(os.path.exists(mp3_nameold)):
os.remove(mp3_nameold)