python爬虫数据保存到本地文件

def parseHtml(html):
	data = {}
    # 创建bs对象 bs是使用的python默认的解析器，lxml也是解析器
	soup = BeautifulSoup(html, 'lxml')
    # find_all(): 可以根据标签名、属性、内容查找文档
	conshoplist = soup.find_all('div', {'class': 'con shoplist'})[0]
	for each in conshoplist.find_all('li'):
		# 书名
		bookname = each.find_all('a')[0].get('title').strip(' ')
		# 书图
		img_src = each.find_all('a')[0].img.get('data-original')
		if img_src is None:
			img_src = each.find_all('a')[0].img.get('src')
		img_src = img_src.strip(' ')
		# 价格
		price = float(each.find_all('p', {'class': 'price'})[0].span.text[1:])
		# 简介
		detail = each.find_all('p', {'class': 'detail'})[0].text
		# 评分
		stars = float(each.find_all('p', {'class': 'search_star_line'})[0].span.span.get('style').split(': ')[-1].strip('%;')) / 20
		# 评论数量
		num_comments = float(each.find_all('p', {'class': 'search_star_line'})[0].a.text[:-3])
		data[bookname] = [img_src, price, detail, stars, num_comments]
        data[bookname].save('d:/new/dangdang_python.csv')
	return data

有什么问题请详细说明