SyntaxError: positional argument follows keyword argument

[buran]

What exactly is Python complaining about, is it use of variable called 'third' which isn't defined before it is referenced in the one liner print statement?

it's complaining because you pass keyword arguments, like 'end' and 'third' (which at later stage will raise unexpected keyword argument error anyway) then positional arguments "And another number:"

the one-liner solution with f-strings is

print(f"The answer is: {int(input('Enter first: ')) + int(input('Enter second: '))}")

but this is really terrible un-pythonic code and I strongly advise against it