How to find the count of a word in a string?

Question

I have a string \"Hello I am going to I with hello am\". I want to find how many times a word occur in the string. Example hello occurs 2 time. I tried this app

Answer 1

from collections import *
import re

Counter(re.findall(r"[\w']+", text.lower()))

Using re.findall is more versatile than split, because otherwise you cannot take into account contractions such as "don't" and "I'll", etc.

Demo (using your example):

>>> countWords("Hello I am going to I with hello am")
Counter({'i': 2, 'am': 2, 'hello': 2, 'to': 1, 'going': 1, 'with': 1})

If you expect to be making many of these queries, this will only do O(N) work once, rather than O(N*#queries) work.

Answer 2

You can use the Python regex library re to find all matches in the substring and return the array.

import re

input_string = "Hello I am going to I with Hello am"

print(len(re.findall('hello', input_string.lower())))

Prints:

2

Answer 3

Considering Hello and hello as same words, irrespective of their cases:

>>> from collections import Counter
>>> strs="Hello I am going to I with hello am"
>>> Counter(map(str.lower,strs.split()))
Counter({'i': 2, 'am': 2, 'hello': 2, 'to': 1, 'going': 1, 'with': 1})