It is exactly the opposite, 0 is falsy, and all other numbers are truthy.

In Python a value of 0 is considered True, while all other numbers are evaluated as False.

This solution certainly gets the job done with minimal characters utilized, but it seems prone to cause needless confusion.

Ditto

Oi! Na sua solução, entendo o refindall(r' mas confesso que fiquei perdido com o resto. O que seria (ou como ler) o (?<=www.)[\w-]*(?=.)"?

Yes. It would be pretty strange if it did not always return the same thing.

Does Counter always return a dictionary?

Guess you could just forget about return and use .get in the end of the dictionary.

Don't understand. Just feel it.

Didn't know about this If Array meaning that there's an array there. That's great.

why would that be inefficient? starting with python now and I used sorted() as well.
what do you mean by "O(n log n)"?