PEP 572: Assignment Expressions (aka Walrus Operator)
Example 4
>>> [(t:=(t[1], sum(t)) if i else (0,1))[0] for i in range(20)]
[0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181]
— Raymond Hettinger (@raymondh) October 13, 2019
https://www.python.org/dev/peps/pep-0572/
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