If we're still talking about Python 3, you can also write,
EURO_SIGN = '\N{EURO SIGN}'
Which is ASCII, and very clear about which character the escape is. I wish more languages had \N. That said, I'm also fine with a coder choosing to write a literal "€" — that's just as clear, to me.
While I don't believe the \N is backwards compatible to Python 2, explicitly declaring the file encoding is, and you can have a UTF-8 encoded source file w/ Python 2 in that way.
I'd also note the box drawing characters are extremely useful for diagrams in comments.
(And… it's 2021. If someone's tooling can't handle UTF-8, it's time for them to get with the program, not for us to waste time catering to them. There's enough real work to be done as it is…)
You can do Unicode in Python 2. You can do Unicode faster and easier in Python 3. But by gaining that ability, they set the existing community back by 10 years.
While I don't believe the \N is backwards compatible to Python 2, explicitly declaring the file encoding is, and you can have a UTF-8 encoded source file w/ Python 2 in that way.
I'd also note the box drawing characters are extremely useful for diagrams in comments.
(And… it's 2021. If someone's tooling can't handle UTF-8, it's time for them to get with the program, not for us to waste time catering to them. There's enough real work to be done as it is…)