Find top 5 word lengths in a text - list

Question

I'm trying to write a program that takes two functions:
count_word_lengths which takes the argument text, a string of text, and returns a default dictionary that records the count for each word length. An example call to this function:
top5_lengths which takes the same argument text and returns a list of the top 5 word lengths.
Note: that in the event that
two lengths have the same frequency, they should be sorted in descending order. Also, if there are fewer than 5 word lengths it should return a shorter list of the sorted word lengths.
Example calls to count_word_lengths:
count_word_lengths("one one was a racehorse two two was one too"):
defaultdict(<class 'int'>, {1: 1, 3: 8, 9: 1})
Example calls to top5_lengths:
top5_lengths("one one was a racehorse two two was one too")
[3, 9, 1]
top5_lengths("feather feather feather chicken feather")
[7]
top5_lengths("the swift green fox jumped over a cool cat")
[3, 5, 4, 6, 1]
My current code is this, and seems to output all these calls, however it is failing a hidden test. What type of input am I not considering? Is my code actually behaving correctly? If not, how could I fix this?
from collections import defaultdict
length_tally = defaultdict(int)
final_list = []
def count_word_lengths(text):
words = text.split(' ')
for word in words:
length_tally[len(word)] += 1
return length_tally
def top5_word_lengths(text):
frequencies = count_word_lengths(text)
list_of_frequencies = frequencies.items()
flipped = [(t[1], t[0]) for t in list_of_frequencies]
sorted_flipped = sorted(flipped)
reversed_sorted_flipped = sorted_flipped[::-1]
for item in reversed_sorted_flipped:
final_list.append(item[1])
return final_list

Answer 1

One thing to note is that you do not account for an empty string. That would cause count() to return null/undefined. Also you can use iteritems() during list comprehension to get the key and value from a dict like for k,v in dict.iteritems():

Answer 2

I'm not a Python guy, but I can see a few things that might cause issues.
You keep referring to top5_lengths, but your code has a function called top5_word_lengths.
You use a function called count_lengths that isn't defined anywhere.
Fix these and see what happens!
Edit:
This shouldn't impact your code, but it's not great practice for your functions to update variables outside their scope. You probably want to move the variable assignments at the top to functions where they're used.

Answer 3

Not really an answer, but an alternative way of tracking words instead of just lengths:
from collections import defaultdict
def count_words_by_length(text):
words = [(len(word),word) for word in text.split(" ")]
d = defaultdict(list)
for k, v in words:
d[k].append(v)
return d
def top_words(dict, how_many):
return [{"word_length": length, "num_words": len(words)} for length, words in dict.items()[-how_many:]]
Use as follows:
my_dict = count_words_by_length('hello sir this is a beautiful day right')
my_top_words = num_top_words_by_length(my_dict, 5)
print(my_top_words)
print(my_dict)
Output:
[{'word_length': 9, 'num_words': 1}]
defaultdict(<type 'list'>, {1: ['a'], 2: ['is'], 3: ['sir', 'day'], 4: ['this'], 5: ['hello', 'right'], 9: ['beautiful']})