how to use Assignment Expressions to check what was matched by any()

Question

I am confused with Assignment Expressions (https://peps.python.org/pep-0572/). According to this question (How to find what matched in any() with Python?) I can use Assignment Expressions to find what was matched by any().

Simple example:


look = "abc"

mylist = ["abcde15", "nonono"]

if any((match := look) in s for s in mylist):
    print(f"I found {look} v {mylist}")

# I found abc v ['abcde15', 'nonono']

But how can I get abcde15 which is what I found in mylist? Thanks

score 1 · Accepted Answer · answered Apr 27 '22 at 10:28

You're assigning match to be the value of look, which is always "abc", hence your result. Instead, you want to figure out which s in mylist was the match, which you can do by using that assignment expression on s instead:

look = "abc"

mylist = ["abcde15", "nonono"]

if any(look in (match := s) for s in mylist):
    print(f"I found {match} v {mylist}")

Which outputs

I found abcde15 v ['abcde15', 'nonono']

how to use Assignment Expressions to check what was matched by any()

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