I can't solve the error: invalid or expired token

[vxcall]

I wrote This code
This code is unfollow "those who are followed me but don't follow me".

I run this... then about after unfollow 120 people, catch the error below.
Get https://api.twitter.com/1.1/friendships/create.json returned status 401, {"errors":[{"code":89,"message":"Invalid or expired token."}]}
after I'm unable to unfollow.

please tell me how to fix this bug.

finally, I think I have difficulty communicating with you because I'm not good at speaking English.
sorry!! :{

[quiye]

@s3pt3mb3r I think it is Twitter's problem.
Please try to regenerate your tokens for unfollowing.

There are people who faced similar problems.
【TwitterAPIのエラー解消法】tweepy.error.TweepError: [{'code': 89, 'message': 'Invalid or expired token.'}] - 仮想化エンジニアの日常

[vxcall]

@quiye
Ok...thank you for your information.