The walrus operator := and assignment expressions, PEP 572, was opposed by majority of Python core developers, and led Guido van Rossum to step down from BDFL role.

LINKS:
PEP 572: https://www.python.org/dev/peps/pep-0572/
Zen of Python: https://www.python.org/dev/peps/pep-0020/
Vote against PEP 572: https://www.mail-archive.com/python-committers@python.org/msg05324.html

OUTLINE:
0:00 - Walrus operator
1:26 - Use cases
3:33 - Criticisms
5:59 - Guido van Rossum