Upper Case and Lower Case

Question

For variable I put str but how do I make it so it says it’s not a string

https://code.sololearn.com/cw63usZB5fDt/?ref=app

Answer 1

Input() returns string by default. So, you don't need to put str() to convert it a string.
If you want to accept texts only, you may try using isalpha() method with if-else statement.

Answer 2

s = "tExT";
u = s.toUpperCase()
d = s.toLowerCase()
in Java Script