从字符串中提取每个单词，而不会在末尾获得额外的空值

def extract_words_from_string(string):
    words = string.split(" ")  # 使用空格作为分隔符拆分字符串
    words = [word.strip() for word in words]  # 去除单词两端的空格
    words = [word for word in words if word]  # 去除空值
    return words

# 示例用法
string = "Hello world, this is a test string."
words = extract_words_from_string(string)
print(words)