Tim Peters wrote:
> Should that raise an exception?

>i += 0

>(?=a)b

>(?=a)a


These are another cases. The first is very special. The second and third are special too, but with different contents of assertion they can do useful work.

While "(?=any contents){N}a" never uses the "{N}" part in any useful manner.


> So I think this report should be closed

I looked into Perl behaviour today, it works like Python. It's not an error there.