如何使我的代码区分单词和单数字符？(Python)

import re

def separate_words_and_chars(text):
    words = re.split(r'\W+', text)  # 使用正则表达式分割单词
    chars = re.findall(r'\b\w\b', text)  # 使用正则表达式匹配单数字符
    return words, chars

text = "Hello, world! This is a sample text."
word_list, char_list = separate_words_and_chars(text)
print("Words:", word_list)
print("Chars:", char_list)

Words: ['Hello', 'world', 'This', 'is', 'a', 'sample', 'text']
Chars: ['a']

def separate_words_and_chars(text):
    words = []
    chars = []
    for char in text:
        if char.isalpha():  # 判断字符是否为字母
            words.append(char)
        elif char.isdigit():  # 判断字符是否为数字
            chars.append(char)
    return words, chars

text = "Hello, world! This is a sample text."
word_list, char_list = separate_words_and_chars(text)
print("Words:", word_list)
print("Chars:", char_list)

Words: ['H', 'e', 'l', 'l', 'o', 'w', 'o', 'r', 'l', 'd', 'T', 'h', 'i', 's', 'i', 's', 'a', 's', 'a', 'm', 'p', 'l', 'e', 't', 'e', 'x', 't']
Chars: ['a']