Question

Following is my coding for count letters and i need the output as

[('e', 1), ('g', 2), ('l', 1), ('o', 2)]

and my out put is

[('e', 1), ('g', 2), ('g', 2), ('l', 1), ('o', 2), ('o', 2)]

This is my code

def countLetters(word):
    word=list(word)
    word.sort()
    trans=[]
    for j in word:
        row=[]
        a=word.count(j)
        row.append(j)
        row.append(a)
        trans.append(tuple(row))
    return trans

can anyone explain me, how to get the expected output with my code?
Thank you

Answer 1

Why not just use a Counter?

Example:

from collections import Counter

c = Counter("Foobar")
print sorted(c.items())

Output:

[(‘F’, 1), (‘a’, 1), (‘b’, 1), (‘o’, 2), (‘r’, 1)]

---

Another way is to use a dict, or better, a defaultdict (when running python 2.6 or lower, since Counter was added in Python 2.7)

Example:

from collections import defaultdict

def countLetters(word):
    d = defaultdict(lambda: 0)
    for j in word:
        d[j] += 1
    return sorted(d.items())

print countLetters("Foobar")

Output:

[(‘F’, 1), (‘a’, 1), (‘b’, 1), (‘o’, 2), (‘r’, 1)]

---

Or use a simple list comprehension

word = "Foobar"
print sorted((letter, word.count(letter)) for letter in set(word))