Could anybody tell me about the use of python3.7 's latest 'walrus operator' ?

Question

The walrus operator (:=) is the new operator 8n python 3.7 release
(It's named so because it looks like the eyes and tusks of a walrus)
I can't figure out its use via the py docs so can anybody tell its use in the codebase ?

Answer 1

https://code.sololearn.com/cC9Sczt5IILR/?ref=app
https://code.sololearn.com/cmJDSvtmVp4Z/?ref=app
https://code.sololearn.com/co16SIK91wbp/?ref=app