Solution Exercice 88: python algorithm which determines the list of characters in s1 not in s2

Exercise 87

Write a Python algorithm as a function which takes as parameter a tuple of two strings (s1, s2) and which returns the list of characters in s1 and not in s2. Example: if s1 = 'Python language' and s2 = 'Java Programming', the function returns the list:

['y', 't', 'h']

Solution

def differenceS1S2(s1 , s2):
    listDifference = []
    for x in s1:
        if x not in s2 and x not in listDifference:
            listDifference.append(x)
    return listDifference
s1 = "Python Programming"
s2 = "Java Programming"
print(differenceS1S2(s1 , s2)) # the output is: ['y', 't', 'h']