Volunteers who make and take care of the Python programming language have decided that January 1, 2020, will be the day that we sunset Python 2.
That means that the people who develop python will not improve it anymore after that day. Even if people find catastrophic security problems in Python 2, or in software written in Python 2, then most volunteers will not help fix them.
The advice is that you should upgrade to Python 3 as soon as you can. If you are maintaining Python 2 only code, please read the official “Porting Python 2 Code to Python 3″ guide.