从字符串中返回单个单词的方法

sentence = "Hello, world! This is a sentence."
words = sentence.split()
print(words)

['Hello,', 'world!', 'This', 'is', 'a', 'sentence.']

import re

sentence = "Hello, world! This is a sentence."
words = re.findall(r'\b\w+\b', sentence)
print(words)

['Hello', 'world', 'This', 'is', 'a', 'sentence']

sentence = "Hello, world! This is a sentence."
words = []
current_word = ""
for char in sentence:
    if char.isalnum():
        current_word += char
    elif current_word:
        words.append(current_word)
        current_word = ""
if current_word:
    words.append(current_word)
print(words)

['Hello', 'world', 'This', 'is', 'a', 'sentence']