I am making a program which checks whether a particular string is an isogram or not.
ISOGRAM: A word which does not have any letter occurring more than once, irrespective of its casing.
Example: Dustbin (every word is occurring once)
(NOTE: The program can also work with random inputs like assdfd)
For example, if the input is
the output should be
False as the ‘o’ has occurred twice(the output has to do with the casing ). But the output is
Therefore, I want to know where am I going wrong. Every suggestion will be appreciated.