Due to political correctness.
Python, like many other programming languages, has the service words master and slave. With the help of them, the interaction between two unequal elements is set, one of which occupies the dominant position over the other.
However, in the version of language 3.8, developers intend to abandon these terms. Depending on the context of the application, the word master will be replaced by parent, main and server (“parent”, “master” and “server”). And the word slave is child and worker (“child” and “worker”).
The release of the new version of the language is tentatively scheduled for October 20, 2019.
Why is it important?
And in Django, a Python-based framework, as early as 2014, the terms master / slave replaced the leader / follower (leader / follower).
However, Python itself is more popular and is used in a variety of large projects of different focus. For example, he is the second most popular language on GitHub.
Because of this, the question arises as to what problems with backward compatibility can lead to the replacement of words.