To get the common letters in two words without repetition

Question

Write the function getCommonLetters(word1, word2) that takes in two words as arguments and returns a new string that contains letters found in both string. Ignore r

Answer 1

You can use set intersection

>>> ''.join(set('apple').intersection(set('google')))
'el'

The function can be defined as

def getCommonLetters(a, b):
    return ''.join(sorted(set(a).intersection(set(b))))

Example

>>> def getCommonLetters(a, b):
...         return ''.join(sorted(set(a).intersection(set(b))))
... 
>>> getCommonLetters('google','apple')
'el'