On Sun, Jan 19, 2020 at 08:32:43AM -0800, Guido van Rossum wrote:
> I'm not excited about suggesting the walrus operator when people want to
> chain mutating method calls like this. It results in ugly code with way too
> many parentheses and a distinctly un-Pythonic flavor. I hope the OP doesn't
> go off and infect a whole subcommunity with this idiom.
It is worse than that: it doesn't even solve the OP's problem of wanting
to chain method calls.
py> (xs := list(range(10))).append(42) # seems to work
py> xs
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 42]
py> (xs := list(range(10))).append(42).append(999)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'append'
--
Steven
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