Walrus operator example in PEP572
问题 One of the examples given in PEP572 is # Reuse a value that's expensive to compute [y := f(x), y**2, y**3] currently in python, you'd have to do one of the following: # option 1 y = f(x) [y, y**2, y**3] or # option 2 [f(x), f(x)**2, f(x)**3] the example implies that option 2 here could be improved, but I have never seen that recommended over the first option. Is there ever a reason why option 2 (and therefore the walrus operator) would be better than option 1? 回答1: Just to make things clear: