How to count digits, letters, spaces for a string in Python?

Question

I am trying to make a function to detect how many digits, letter, spaces, and others for a string.

Here's what I have so far:

def count(x):
    length = len(x)
    digit = 0
    letters = 0
    space = 0
    other = 0
    for i in x:
        if x[i].isalpha():
            letters += 1
        elif x[i].isnumeric():
            digit += 1
        elif x[i].isspace():
            space += 1
        else:
            other += 1
    return number,word,space,other

But it's not working:

>>> count(asdfkasdflasdfl222)
Traceback (most recent call last):
  File "<pyshell#4>", line 1, in <module>
    count(asdfkasdflasdfl222)
NameError: name 'asdfkasdflasdfl222' is not defined

What's wrong with my code and how can I improve it to a more simple and precise solution?

Solution 1

Here's another option:

s = 'some string'

numbers = sum(c.isdigit() for c in s)
letters = sum(c.isalpha() for c in s)
spaces  = sum(c.isspace() for c in s)
others  = len(s) - numbers - letters - spaces

Solution 2

Following code replaces any nun-numeric character with '', allowing you to count number of such characters with function len.

import re
len(re.sub("[^0-9]", "", my_string))

Alphabetical:

import re
len(re.sub("[^a-zA-Z]", "", my_string))

More info - https://docs.python.org/3/library/re.html

Solution 3

You shouldn't be setting x = []. That is setting an empty list to your inputted parameter. Furthermore, use python's for i in x syntax as follows:

for i in x:
    if i.isalpha():
        letters+=1
    elif i.isnumeric():
        digit+=1
    elif i.isspace():
        space+=1
    else:
        other+=1

Solution 4

# Write a Python program that accepts a string and calculate the number of digits 
# andletters.

    stre =input("enter the string-->")
    countl = 0
    countn = 0
    counto = 0
    for i in stre:
        if i.isalpha():
            countl += 1
        elif i.isdigit():
            countn += 1
        else:
            counto += 1
    print("The number of letters are --", countl)
    print("The number of numbers are --", countn)
    print("The number of characters are --", counto)

View more solutions

Comments

[Óscar López]

@sundarnatarajСундар it's a trade-off. Sure, it iterates 3 times over the input string, but I believe it's easier to read like this.

[Raymond Hettinger]

+1 The solution is cleaner when you separate the tasks. Nice work! To make it fast, consider using itertools.imap() like this: numbers = sum(imap(str.isdigit, s)). After the initial calls, that will run at C-speed with no pure python steps and no method lookups.

[ray]

the indentation is right( got wrong when copy to stackoverflow). the reason I used x=[] is try to let Python know that x is a list. if I delete x=[], it showed : >>> count(aasdfs1111xxx) Traceback (most recent call last): File "<pyshell#250>", line 1, in <module> count(aasdfs1111xxx) NameError: name 'aasdfs1111xxx' is not defined

[ray]

HI, If I removed x = [], the it got error when I run. it said the strings I typed is " not defined".

[Abhishek Mittal]

I execute this code by comment out x = [] and it is working fine. One more error in your code is that you need to use isdigit instead of isnumberic. Here, I am assuming that count function is called by passing string in x argument. Like : count ("1233AASD 43") Please let me know if it does not solve your problem.

[Massimiliano Kraus]

Welcome to StackOverflow. You better explain your solution, instead of just posting anonymous code. Maybe you should read How do I write a good answer, especially when it says Brevity is acceptable, but fuller explanations are better.

[Óscar López]

@ShubhamS.Naik True is taken as 1 for the purpose of a sum

[Shubham S. Naik]

Thanks @ÓscarLópez I agree that True is taken as 1, however I want to know numbers = sum(c.isdigit() for c in s) is generating which iterable?? As sum(1) returns as below: >>> sum(1) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'int' object is not iterable

[Óscar López]

The inside of sum is a generator expression, I simply removed the surrounding () because they’re redundant

[Shubham S. Naik]

@ÓscarLópez which data structure (iterable) does it generate ?

[Óscar López]

As I said: a generator expression. Read about it in the docs.

[Shubham S. Naik]

@ÓscarLópez I will read about 'generator expression' . Thanks a lot !!

[Tim]

This doesn't actually answer the question. The question was to count the number of digits, letters and spaces, not to find all instances of numbers.