Once again convinced that regex patterns are powerful instrument

The only thing that confused this type of database list or dict. The author does not give a direct indication of the database typing.

I like to solve such tasks, I spent about 2 hours on the last ISBN10 calculation task, I won’t say that my calculation is optimal, but I always try to write my code more understandable for everyone, even if it eats a little more memory, but the experience is adaptation and optimization comes with age.