Finding the most frequent character in a string

Question

I found this programming problem while looking at a job posting on SO. I thought it was pretty interesting and as a beginner Python programmer I attempted to tackle it. Howe

Answer 1

def most_frequent(text):
    frequencies = [(c, text.count(c)) for c in set(text)]
    return max(frequencies, key=lambda x: x[1])[0]

s = 'ABBCCCDDDD'
print(most_frequent(s))

frequencies is a list of tuples that count the characters as (character, count). We apply max to the tuples using count's and return that tuple's character. In the event of a tie, this solution will pick only one.