# 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.

# isIsogram( "Dermatoglyphics" ) == true

# isIsogram( "aba" ) == false

# isIsogram( "moOse" ) == false // -- ignore letter case

# My solution

def is_isogram(string):

if not string:

return True

else:

text = string.lower()

for i in text:

count = text.count(i, 0, len(text)+1)

if count > 1 :

return False

return True

# Best solutions

def is_isogram(string):

return len(string) == len(set(string.lower()))