We are volunteers who make and take care of the Python programming language. We have decided that January 1, 2020, will be the day that we sunset Python 2. That means that we will not improve it anymore after that day, even if someone finds a security problem in it. You should upgrade to Python 3 as soon as you can.
I wrote code in Python 2. How should I port it to Python 3?
Please read the official "Porting Python 2 Code to Python 3" guide. Please also read the Python 3 Statement Practicalities for advice on sunsetting your Python 2 code.