如何打印只包含字符串中字母的单词？

import re

def print_words_with_letters_only(sentence):
    # 拆分字符串为单词列表
    words = sentence.split(" ")

    # 遍历单词列表
    for word in words:
        # 使用正则表达式匹配单词中是否只包含字母
        if re.match("^[a-zA-Z]+$", word):
            print(word)

# 测试代码
sentence = "Hello, 123 world! Only print words with letters."
print_words_with_letters_only(sentence)

Hello
world
Only
print
words
with
letters