consider-using-f-string produces worse quality code in some cases

[doublethefish]

Bug description

consider-using-f-string produces worse quality code in some cases, for example consider the following format string:

            "Timing of '{name}' took {secs}s/{total_secs}s (started {start_time})".format(
                name=name,
                secs=delta.total_seconds(),
                total_secs=self._config.timeout_seconds,
                start_time=self._start_time.strftime("%H:%M:%S %Z").strip(),
            )

Any variant of using an f-string to remove the consider-using-f-string warning does one of the following:

• causes more local variables to be created (possibly blowing the max-locals limit)
• is less readable (as the context of what the pieces are intended for is lost, e.g. took {secs}s/{total_secs}s is significantly more readable than took {delta.total_seconds()}s/{self._config.timeout_seconds}s
• splits the context over multiple lines, making it harder to read the context

Configuration

No response

Command used

python3 -m pylint -j4 --score=n --rcfile=.pylintrc <files>

Pylint output

[..snip..]
C0209: Formatting a regular string which could be a f-string (consider-using-f-string)
[..snip..]

Expected behavior

Only emit the warning for invocations of str.format that are below a certain complexity i.e. 5 parameters.

Additionally only emit the warning when the conformed string is

1. within line-width limits (including indents), or
2. roughly the same length as the string it would replace - say maximally 10% larger than the existing string (as f-strings are smaller in most cases).

Pylint version

pylint 2.11.1
astroid 2.8.2
Python 3.10.0 (default, Oct  6 2021, 00:30:31) [GCC 10.3.1 20210424]

OS / Environment

n/a but
Alpine Linux 9b0fb0d01a22 5.10.47-linuxkit #1 SMP PREEMPT Sat Jul 3 21:50:16 UTC 2021 aarch64 Linux
bash

Additional dependencies

No response

[doublethefish]

Closing as most of this has already been considered in #5039, although not all points are directly considered.

[Pierre-Sassoulas]

Thank you for searching for other issue related to that @doublethefish 😄. For reference if someone happen to see this issue following a search, in the example given it's possible to do:

            template = "Timing of '{name}' took {secs}s/{total_secs}s (started {start_time})"
            template.format(
                name=name,
                secs=delta.total_seconds(),
                total_secs=self._config.timeout_seconds,
                start_time=self._start_time.strftime("%H:%M:%S %Z").strip(),
            )

And not have any warnings raised.