[Python] Quiz question?

Question

I really don't know what to place in there. Could you help me, please ?

https://code.sololearn.com/Wa247A226a18/#

Thanks for your time.

Answer 1

Please close the img tag to understand your question clearly
https://www.sololearn.com/Discuss/2628154/?ref=app

Answer 2

▲TopGun ▲, I think you should fill -> len.