Answer to Question #344738 in Python for Rogger

Question

Write a function called has_duplicates that takes a string parameter and returns True if the string has any repeated characters. Otherwise, it should return False.  

Implement has_duplicates by creating a histogram using the histogram function above. Do not use any of the implementations of has_duplicates that are given in your textbook. Instead, your implementation should use the counts in the histogram to decide if there are any duplicates. 

Write a loop over the strings in the provided test_dups list. Print each string in the list and whether or not it has any duplicates based on the return value of has_duplicates for that string. For example, the output for "aaa" and "abc" would be the following. 

aaa has duplicates

abc has no duplicates 

Print a line like one of the above for each of the strings in test_dups. 

Answer 1

def histogram(s):
    d = dict()
    for c in s:
        if c not in d:
            d[c] = 1
        else:
            d[c] += 1
    return d


def has_duplicates(s):
    for v in histogram(s).values():
        if v > 1:
            return True
    return False


def test_dups_loop():
    for s in test_dups:
        print(s + ':', has_duplicates(s))


# test


test_dups = ["zzz","dog","bookkeeper","subdermatoglyphic","subdermatoglyphics"]
test_dups_loop()