How to return maximum of value in a tuple within a list within a dictionary?-CodePudding

This is an excercise from the book Python Workout by R.M Lerner.

I'm struggling to return a maximum value of the following code:

def most_repeating_word(ls):
    listed = [x for x in ls.split()]
    outcome = {}
   
    for word in listed:
        max_char = []
        char_set = []
        for char in word:
            if char not in char_set:
                char_set.append(char)
                count = word.count(char)
                max_char.append((char,count))
        
        outcome[word] = (max_char)

    return max(outcome, key = lambda x: x[1])

most_repeating_word('this is an elementary test example')

The function should return the word with highest repeating element, in this case "elementary" with e=3, but it returns "example".

I think the reason is that it compares second letters of the words, and returns 'x' as the max. I fail to understand how to access the tuples values. Using outcome.values in the return part does not help.

CodePudding user response：

We can use for loop on outcome dictionary to check which letter in which word repeated the most.

The code

def most_repeating_word(ls):
    listed = [x for x in ls.split()]
    outcome = {}
   
    for word in listed:
        max_char = []
        char_set = []
        for char in word:
            if char not in char_set:
                char_set.append(char)
                count = word.count(char)
                max_char.append((char,count))
        
        outcome[word] = (max_char)
    
    repeating_word = ''
    repeating_letter = ''
    max_char_count = 0
    for key in outcome:
        for letter in outcome[key]:
            if letter[1] > max_char_count:
                repeating_word = key
                repeating_letter = letter[0]
                max_char_count = letter[1]

    return [repeating_word, repeating_letter, max_char_count]


data = most_repeating_word('this is an elementary test example')

print(f"The word {data[0]} ham most repeated letter {data[1]} which occurs {data[2]} times")

Output

The word elementary ham most repeated letter e which occurs 3 times

CodePudding user response：

Since outcome is a dictionary of lists of tuples, you need two max() to find the word with the highest repeating element. The first max() finds the count of the highest repeating element in a word, and the second max() finds the word with the highest count.

Preserving the data structure you use, the key argument needs to look like this: lambda word_maxchar: max(word_maxchar[1], key = lambda char_count: char_count[1])[1]. The whole code would look like this:

def most_repeating_word(ls):
    listed = [x for x in ls.split()]
    outcome = {}
   
    for word in listed:
        max_char = []
        char_set = []
        for char in word:
            if char not in char_set:
                char_set.append(char)
                count = word.count(char)
                max_char.append((char,count))
        
        outcome[word] = (max_char)

    return max(outcome.items(), key = lambda word_maxchar: max(word_maxchar[1], key = lambda char_count: char_count[1])[1])[0]

most_repeating_word('this is an elementary test example')

Also note that in order to iterate over both keys and values of a dictionary, you need to use outcome.items().

With a little modification of your data structure, we can achieve slightly better readability of the code:

def most_repeating_word(ls):
    listed = [x for x in ls.split()]
    outcome = {}
   
    for word in listed:
        max_char = []
        char_set = []
        for char in word:
            if char not in char_set:
                char_set.append(char)
                count = word.count(char)
                max_char.append((char,count))
            
        
        outcome[word] = max(max_char, key = lambda char_count: char_count[1])

    return max(outcome.items(), key = lambda x: x[1][1])[0]

most_repeating_word('this is an elementary test example')