Python f-string clarification

I am wondering how I could convert len of a variable consisting of a list into a string using f-string. An example is this:
str(len(names).
I tried this with the curly braces like this
{str(len(names)}
and other variations but it doesn’t work. I would very much appreciate your help. Many thanks in advance.

>Solution :

It’s pretty straightforward. The explicit conversion with str is unnecessary.

>>> names = ['foo', 'bar']
>>> f"{len(names)}"
'2'
>>>