What if "hello {x}" is not a static string but was read from somewhere else?

Surely this would not work:

  greeting = "hello {x}"
  greet = lambda x: f greeting

Something along the lines of...

    code = 'f"{input()} {x}"'

    lambda x: eval(code)

(Please don't do this)

    code = 'f"here it is {eval(input())}"'
    (lambda: eval(code))()

k, there we go

Yes, I'll stick to using str.format :)

That isn't the purpose for f-strings. You still have % and .format

You can’t use f-strings for that.

That was exactly my point.