Get the number of occurrences of each character

Question

Given the string:

a='dqdwqfwqfggqwq'

How do I get the number of occurrences of each character?

This has a bunch of other ways, defaultdict is a nice way of doing it without counter (2.5+) http://stackoverflow.com/questions/991350/counting-repeated-characters-in-a-string-in-python — Andrew Barrett, May 06 '12 at 18:29

score 18 · Answer 1 · answered Mar 04 '11 at 10:57

18

In 2.7 and 3.1 there's a tool called Counter:

>>> import collections
>>> results = collections.Counter("dqdwqfwqfggqwq")
>>> results
Counter({'q': 5, 'w': 3, 'g': 2, 'd': 2, 'f': 2})

Docs. As pointed out in the comments it is not compatible with 2.6 or lower, but it's backported.

answered Mar 04 '11 at 10:57

Bjorn

5,272
1
24
35

12

Jakob, if you want one line: import collections; collections.Counter("dqdwqfwqfggqwq") Ta-dah. :) – Bjorn Mar 04 '11 at 11:01

score 17 · Accepted Answer · answered Mar 04 '11 at 11:15

17

Not highly efficient, but it is one-line...

In [24]: a='dqdwqfwqfggqwq'

In [25]: dict((letter,a.count(letter)) for letter in set(a))
Out[25]: {'d': 2, 'f': 2, 'g': 2, 'q': 5, 'w': 3}

answered Mar 04 '11 at 11:15

unutbu

842,883
184
1,785
1,677

It's O(N * sigma) where sigma is number of unique letters; nice improvement – John Machin Mar 04 '11 at 11:20
1

Code golf: `count=lambda s:dict((c,s.count(c)) for c in set(s))` – Mr. Polywhirl Dec 16 '14 at 12:04
Better Code golf: count=lambda x:{t:x.count(t)for t in x} – Gareth Ma Aug 24 '18 at 08:42

score 3 · Answer 3 · answered Jun 10 '18 at 11:42

You can do this:

listOfCharac={}
for s in a:
    if s in listOfCharac.keys():
        listOfCharac[s]+=1
    else:
        listOfCharac[s]=1
print (listOfCharac)

Output {'d': 2, 'f': 2, 'g': 2, 'q': 5, 'w': 3}

This method is efficient as well and is tested for python3.

score 0 · Answer 4 · answered Nov 23 '17 at 23:01

0

lettercounts = {}
for letter in a:
    lettercounts[letter] = lettercounts.get(letter,0)+1

answered Nov 23 '17 at 23:01

Ashraf Choudhury

21
1
4

Frost.baka · Answer 5 · 2011-03-04T11:06:41.710

0

For each letter count the difference between string with that letter and without it, that way you can get it's number of occurences

a="fjfdsjmvcxklfmds3232dsfdsm"
dict(map(lambda letter:(letter,len(a)-len(a.replace(letter,''))),a))

edited Mar 04 '11 at 11:06

answered Mar 04 '11 at 11:00

Frost.baka

7,851
2
22
18

3

Hey, no one is talking about efficiency, only about size :) – Frost.baka Mar 04 '11 at 11:18
1

`a.count(letter)` is clearer than `len(a)-len(a.replace(letter,''))` if you want *that way you can get it's number of occurences* – eumiro Mar 04 '11 at 11:19

score 0 · Answer 6 · edited Feb 05 '21 at 12:10

0

python code to check the occurrences of each character in the string:

word = input("enter any string = ")
for x in set(word):
    word.count(x)
    print(x,'= is', word.count(x))

Please try this code if any issue or improvements please comments.

edited Feb 05 '21 at 12:10

Brian Tompsett - 汤莱恩

5,753
72
57
129

answered Feb 05 '21 at 11:44

jagadeesh

1
1

score -1 · Answer 7 · answered Mar 14 '18 at 20:24

-1

one line code for finding occurrence of each character in string.

for i in set(a):print('%s count is %d'%(i,a.count(i)))

answered Mar 14 '18 at 20:24

Abhay Gupta

1
1

Get the number of occurrences of each character

7 Answers7

Linked

Related