有没有一种更简单的方法来保留句子中的字符，但保持单词的顺序不变？

import re

def preserve_characters(sentence):
    # 分割句子成单词数组
    words = sentence.split(" ")
    preserved_words = []

    for word in words:
        # 使用正则表达式匹配并提取单词中的字符
        preserved_word = re.sub(r"[^a-zA-Z]", "", word)
        preserved_words.append(preserved_word)

    # 重新组合单词成新的句子
    preserved_sentence = " ".join(preserved_words)

    return preserved_sentence