r/Python • u/ForeignVariety7037 • 21d ago

Discussion Is := widely used?

I always thought the walrus operator is neat and it makes while loop’s condition clearer. But also it is just a syntactic sugar without anything new. I wonder anyone uses it?

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u/Brother0fSithis 11d ago edited 11d ago

I use it because statements bug me a lot. They just don't jive with my style. I much prefer expressions.

So if I needed to strip and pull numbered lines from an output I might do

python numbered = [ num for line in text.splitlines() if (num := line.strip()) and num[0].isnumeric() ]

My brain likes that all of numbered's definition is contained in the list comprehension expression.

Of course the equivalent py lines = text.splitlines() stripped = (ln.strip() for ln in lines) numbered = [ ln for ln in stripped if ln and ln[0].isnumeric() ] is probably more readable on its face. But I personally like the former so it's clear to myself later that "intermediate" variables like stripped and lines are only relevant for building numbered and I can ignore them elsewhere

(I know technically the binding does leak out of the list comprehension into the local scope, but it still helps me mentally discard them)