如何从句子中计算相同的单词？

Question

I want to ask how to count the same words from sentences(In Python).

As for an example, from a sentence like: "What a wonderful day. Birds are singing, children are laughing."

What I want to extract is: ['what':1, 'a':1, 'wonderful':1, 'dat':1, 'birds':1, 'are':2, 'singing':1, 'children':1, 'laughing':1]

I have made here:

sent = "What a wonderful day. Birds are singing, children are laughing."
b = set([word.lower() for word in a])
c = list(b)

If this code isn't appropriate for the job, please let me know. Thank you.

Answer 1

Use collections.Counter + string.strip to strip punctuations:

from collections import Counter
import string

sent = "What a wonderful day. Birds are singing, children are laughing."

c = Counter([x.strip(string.punctuation) for x in sent.split()])
print(c)

# Counter({'are': 2, 'What': 1, 'a': 1, 'wonderful': 1, 'day': 1, 'Birds': 1, 'singing': 1, 'children': 1, 'laughing': 1})

If you want this to be case insensitive, transform to lowercase before finding the count, like below:

s = sent.translate(str.maketrans('', '', string.punctuation))

Answer 2

You can use counter and re for this

import re
from collections import Counter
remove_punctutation = re.findall("[A-Za-z]+",sent)
print(dict(Counter(remove_punctutation)))
#{'What': 1,'a': 1,'wonderful': 1,'day': 1,'Birds': 1,'are': 2,'singing': 1,'children': 1,'laughing': 1}

Answer 3

collections.Counter can be used to count occurences of anything in a list. That is a good start. That means, however that we should first make the sentence into a list of words and remove punctuation.

To make a list of the words, there is a method called .split() which will split the sentence on white spaces. And to remove punctuation, the methos .strip() is a good choice.

As you already hint at, we should also normalize the case. For this, it is better to use .casefold() rather than .lower() . In some locals these will not be identical.

All-in-all that leads to code looking somewhat like:

import string
from collections import Counter

sent = "What a wonderful day. Birds are singing, children are laughing."
words = [word.strip(string.punctuation).casefold() for word in sent.split()]
freq = Counter(words)