counting letter frequency with a dict

Question

I'm trying to find the frequency of letters without the Counter.And the code will output a dictionary form of result. And what I have done so far is to make the program count the word frequencies but not the letter/character frequencies. If anyone could point out my mistakes in this code that would be wonderful. Thank you. It supposed to look like this:

{'a':2,'b':1,'c':1,'d':1,'z':1}

**but this is what I am actually getting:

{'abc':1,'az':1,'ed':1}

**my code is below

word_list=['abc','az','ed']
def count_letter_frequency(word_list):
  letter_frequency={}
  for word in word_list:
    keys=letter_frequency.keys()
    if word in keys:
        letter_frequency[word]+=1
    else:
        letter_frequency[word]=1
  return letter_frequency

Twentyone

You’re iterating over a list of words but calling each item a letter. Perhaps if you renamed to for word in word_list: it would be more obvious what the problem is and how to solve it. Naming is important! – Jemena

Answer 1

This is the correct code:

word_list=['abc','az','ed']

def count_letter_frequency(word_list):
  letter_frequency={}
  for word in word_list:
    for letter in word:
      keys=letter_frequency.keys()
      if letter in keys:
          letter_frequency[letter]+=1
      else:
          letter_frequency[letter]=1
  return letter_frequency

You were iterating over the list and the list contains words. So, you were making words as keys in your dictionary. So, you have to add another for loop to iterate over the letters in each word.

Slick

I added another for loop in and it worked! All I ever needed is this extra loop. Thank you for helping me with this. – Twentyone

Please accept this answer as best answer if it solved your problem. – Slick

Answer 2

Use collections.Counter

from collections import Counter

print Counter(''.join(word_list))
# Counter({'a': 2, 'c': 1, 'b': 1, 'e': 1, 'd': 1, 'z': 1})

Or count the elements yourself if you don't want to use Counter.

from collections import defaultdict

d = defaultdict(int)
for c in ''.join(word_list):
    d[c] += 1
print d
# defaultdict(<type 'int'>, {'a': 2, 'c': 1, 'b': 1, 'e': 1, 'd': 1, 'z': 1})

Tortuosity

I was trying to do this without the collection.Counter. But this is still helpful. Thank you – Twentyone

Answer 3

Would this be acceptable:

flat = ''.join(word_list)
{l: flat.count(l) for l in set(flat)}
#{'a': 2, 'b': 1, 'c': 1, 'd': 1, 'e': 1, 'z': 1}

If you would prefer this in for loop, here it goes:

flat = ''.join(word_list)
result = {}
for l in flat:
    if l in result:
        result[l] += 1
    else:
        result[l] = 1

Winged