I added an idea with uppercase and lowercase letters. Thanks!

Thanks for this comment! I will add the information to the description

Digits. I will add a range

of course you are right that they are related but they are from level 4 and 5. My kata is the fundamental operations on the lists and dictionary. I will correct it and publish again. Thanks for your comment!

Hi,
Thank you very much for your comment! This is my first published kata. (I have to learn a lot :))

Regarding your comments:

1. Of course I forgot in the tests that a whitespace is added at the end of the text - I will correct it
2. if you consider it necessary, I will add permanent tests
3. I will increase the number of random tests
4. This is only about digits but I can add info about "range"
5. I could not confirm that it is a duplicate because I did not find same kata - if you can please send me a url to this kata.