[hultner]

You're allowed to do assignments inside of expressions

E.g.

    if(x:=f() is not None):
        print(x)

You can read more about it here: https://www.python.org/dev/peps/pep-0572/

[majewsky]

I'm immediately skeptical after seeing this example because I'm not sure if the first line parses as:

  if (x := f()) is not None:

or as:

  if x := (f() is not None):

[sametmax]

That's why parenthesis are mandatory.

[icebraining]

:= overrules everything except a comma, so it's the latter. Still, I agree it's potentially confusing.