You do multiline strings with 3 quotes, e.g.:

some_var = “string”
s = f"""
This is a very very very very very very very very very
very very very very very very long {some_var}.
"""

If you don’t want line breaks, you can also do

some_var = “string”
s = (
  f”This is a very very very very very very very very very”
  # note the leading space here
  f” very very very very very very long {some_var}.”
)

But doing it the way shown will render the string something like:

This is a very very very very very very very very very      very very very very very very long {some_var}.

That big block of white space in the middle is not desired.