Lower & upper (2) X86558

The statement is exactly the same as problem X23315: write a function @lowupp(info)@ that expects to receive a string; if it starts with the character @’^’@, then it returns the rest of the string in upper case; if it starts with the character @’_’@, then it returns the rest of the string in lower case; if it starts anyhow else, it returns the string unchanged.

The little difference is the following: in case you solved X23315 using the method @startswith()@ from the class @str@, now you are requested not to use it, nor any other method from @str@ beyond, of course, @upper()@, @lower()@, and indexing. Be careful with limit cases!

Sample session