Yes, not welcome.PEP8
, subsection “Other recomendations”:
Compound statements (multiple statements on the same line) are generally discouraged.
However, later in PEP8 there is a comment:
While sometimes it's okay to put an if/for/while with a small body on the same line, ...
But in practice, any reviewer will reject the record. For a colon inside a complex expression must follow a new line, so you can easily distinguish it from the colon in a type annotation or, say, a dict comprehension. So what
− it is rather a no-no than sometimes ok.