In this case ("11 y.o") you can use a "split"-method 'int(s.split()[0])'
But task is very specific (from 0 to 9).

Because the reply is coming as a string, and the condition is that first character is always a number. Thus you want only the first character exported from the given string.

could you explain why you use [0]?

nice! I solved it differently and it's interesting how you solve it

Yeah, but the description clearly says "first character will be the desired answer" so while your approach is more correct (or best practice) and solves wider problem, the task itself was much simpler in this case.

nice job

I also solved it.

I have The same input. But this will not work on other type of strings like "i am 7 years".

No need for expansion.

The description already said 0-9 only required.

Code might not work for age >= 10. By using age[0], you are only obtaining the first index of the string, which in this case is the age, assumed to be less than 10. "Specification said it will be digit (0 through 9)." Make your code expandable!

Specification said it will be digit (0 through 9).

and what about e.g "11 years old"?