Isograms

An isogram is a word that has no repeating letters, consecutive or non-consecutive. Implement a function that determines whether a string that contains only letters is an isogram. Assume the empty string is an isogram. Ignore letter case.

Example: (Input --> Output)

"Dermatoglyphics" --> true
"aba" --> false
"moOse" --> false (ignore letter case)

 

---

def is_isogram(string):
    string=string.upper()
    for i in range(len(string)):
        print(string[i::])
        if string[i] in string[i+1::]:
            return False
    return True