python: sanitize number formatting

[axel-h]

• Fix the calculation of leading zeros. Using "int(log10(cnt + 1)) + 1" is broken, it evaluates to 2 for cnt=9, and thus results in the strings "00"-"08". Using "1 if (n <= 1) else (1 + int(log10(n - 1)))" seems overly complicated here, so a naive and readable way is used.
• switch to f-strings for better readability

[lsf37]

I usually like f-strings, but you're now duplicating the format a bunch of times. Is that really better?

[lsf37]

Looking at it more deeply, @kent-mcleod was pointing out that this is a breaking change, because it changes the names in the generated capDL spec.

It's not catastrophic, but it will make it harder for people to migrate between versions, because it introduces unnecessary change. Not that people should rely on the names, but I'm sure some things do.

If this was fixing an actual problem it would make sense to look into it and accept that potential additional work for people, but doing that for the purely aesthetic reason to get the right number of leading zeroes in an artefact that is usually not for human consumption is not worth it, so I don't think we should merge this PR.

I'd be up for adding a comment that we know it's not the right number, but that we currently don't want to break spec compatibility.

[axel-h]

Actually, this is a follow-up on my PR comment #104 (comment) but the changes there got merged already, and this was not addressed.
So, while this is another breaking change, it "fixes" things to the intention of that PR. The f-strings try to make it a bit less obscure, we can drop this part.
I agree it is just aesthetic in the end, and unfortunately I did not find the time to make the PR earlier. However, there has not been any release since then, so for the upcoming release it's all a breaking change anyway.