How to change the voice in pyttsx3?

You can try this code:

import pyttsx3
engine = pyttsx3.init()
voices = engine.getProperty('voices')
for voice in voices:
    print(voice, voice.id)
    engine.setProperty('voice', voice.id)
    engine.say("Hello World!")
    engine.runAndWait()
    engine.stop()

Then instead of the for loop, just pick up your preferred voice.id

I have just noticed. To set the language⇓ This is just my default language setting is 'ja_JP'.

import pyttsx3

engine = pyttsx3.init()
voices = engine.getProperty('voices')
for voice in voices:
    print voice
    if voice.languages[0] == u'en_US':
        engine.setProperty('voice', voice.id)
        break

engine.say('Hello World')
engine.runAndWait()

or

voice.name == 'Alex'