Unfortunately random.choice isn't available in MicroPython on the ESP8266 -- it's one of the things that gets removed on the smaller microcontrollers, otherwise there wouldn't be enough room (but it is enabled on ESP32 and STM32).
On ESP8266, all you get is random.getrandbits().
But you can implement random.choice yourself -- it's the same as
def choice(x):
return x[randrange(0, len(x)]
And randrange (to get a random number between two numbers) can be copied from
https://github.com/micropython/micropyt ... /random.py