Q23Multiple correct3 Marks11 Dec 2022
An isogram is a word without a repeating letter.
Examples of isograms:
- background
- downstream
However, the word isograms is not an isogram, because the letter 's' appears twice.
Which of the following code fragment(s) can be used to complete the function is_isogram?
```
def is_isogram(string):
nstr = string.lower()
unique = True
for x in range(0, len(nstr)):
### Missing code ###
unique = False
break
return unique
```