After a comprehensive discussion among Python developers, pep 572proposed assignment expressions. This property provides a new operator (: =) to which you can assign variables in an expression.
Positional arguments only
In Python, you can pass an argument to a function in position, keyword, or both. API designers sometimes want to limit the passing of arguments only by their position. To easily implement this, Python 3.8 comes with a new marker (/) to indicate that the arguments to the left are positional only. This is similar to the * sign, which indicates that the arguments to the right are just keywords.
Python Startup Configuration
Python is highly configurable, but configurations are scattered around all the code. This release provides python developers with new functionality and structures to the Python Launch C API to provide a "simple and reliable way" to configure Python.
Vectorcall protocol for CPython
A search agreement significantly affects the flexibility and performance of your code. To optimize the call of objects, this release introduces the Vectorcall protocol and a call rule that is already used internally for Python and internal functions.
Runtime control hooks
Python 3.8 will come with two new APIs: Control Hook and Verified Hook Open to give you an insight into a running Python application. These will make it easier for app developers and system administrators to integrate Python into existing monitoring systems.
Because this is a beta version, developers should avoid using it in production environments. The next beta version is currently scheduled for release on July 1.