如何从没有标题的span标记中提取文本？

from bs4 import BeautifulSoup

def extract_text_from_span(html):
    soup = BeautifulSoup(html, 'html.parser')
    spans = soup.find_all('span')
    extracted_text = []
    
    for span in spans:
        if not span.contents:
            extracted_text.append(span.text)
        else:
            text = extract_text_from_children(span)
            extracted_text.append(text)
    
    return extracted_text

def extract_text_from_children(element):
    text = ''
    for child in element.children:
        if child.name == 'span':
            text += extract_text_from_children(child)
        else:
            text += child.string or ''
    return text

# 示例用法
html = '<div><span>这是一个<span>没有标题的</span>span标记</span></div>'
extracted_text = extract_text_from_span(html)
print(extracted_text)