Solution Exrcise 89: python program which determines the list of all repeated charcters

Exercise 89

Write a Python algorithm which determines the list of repeated charcters in given string. Example: if s = "Programming language", the algorithm returns the list:

['r', 'g', 'a', 'm', 'n']

Solution

# create a function to test if given character is repeated within a given string
def isRepeated(s,c):
    counter = 0
    for x in s:
        if x == c:
            counter = counter + 1
    if counter >= 2:
        return True
    else:
        return False
# create a function that returns the list of all repeated characters
def repeated(s):
    # initializing the list of all repeated characters
    listRepeated = []
    for x in s:
        if isRepeated(s , x) and x and x != " " and x not in listRepeated:
            listRepeated.append(x)
    return listRepeated

# Example
s = "programming language"
print("List of repeated characters in s: " , repeated(s)) 
# The output is : List of repeated characters in s:  ['r', 'g', 'a', 'm', 'n']