写一个爬虫当当网书籍数据的爬虫程序

好的，以下是一个爬取当当网的图书数据的示例爬虫程序：

import requests
from bs4 import BeautifulSoup
import csv

def get_book_info(book_url):
    """获取图书信息"""
    res = requests.get(book_url)
    soup = BeautifulSoup(res.text, 'html.parser')
    book_info = {}
    book_info['title'] = soup.select_one('.name_info h1').text.strip()
    book_info['author'] = soup.select_one('.author span a').text.strip()
    book_info['publisher'] = soup.select_one('.publisher_info a').text.strip()
    book_info['pub_date'] = soup.select_one('.publisher_info span').text.strip()
    book_info['price'] = soup.select_one('.price_info .price_r').text.strip()
    return book_info

def crawl_dangdang_books():
    """爬取当当网图书数据"""
    # 构造请求头部信息
    headers = {
        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3'}
    # 构造请求参数信息
    params = {
        'category_path': '01.00.00.00.00.00',
        'sort_type': 'sort_default',
        'page_index': '1'
    }
    # 发送请求获取页面数据
    res = requests.get('http://category.dangdang.com/', headers=headers, params=params)
    soup = BeautifulSoup(res.text, 'html.parser')
    # 获取总页数
    total_page = int(soup.select_one('.page .total').text[1:-1])
    # 保存图书数据到CSV文件
    with open('dangdang_books.csv', 'w', newline='', encoding='utf-8') as csvfile:
        fieldnames = ['title', 'author', 'publisher', 'pub_date', 'price']
        writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
        writer.writeheader()
        # 爬取每一页的数据
        for page in range(1, total_page+1):
            params['page_index'] = str(page)
            res = requests.get('http://category.dangdang.com/pg'+str(page)+'-cp01.00.00.00.00.00.html', headers=headers, params=params)
            soup = BeautifulSoup(res.text, 'html.parser')
            # 爬取每一页的图书数据
            book_items = soup.select('.bigimg .pic')
            for book_item in book_items:
                book_url = book_item.select_one('a')['href']
                book_info = get_book_info(book_url)
                writer.writerow(book_info)
            print('已爬取第 %d 页的数据' % page)

if __name__ == '__main__':
    crawl_dangdang_books()

此程序使用requests库发送HTTP请求，并使用BeautifulSoup库解析爬取到的HTML页面。它从当当网的图书分类页开始，爬取每一页的图书数据，并将结果保存到CSV文件中。程序中还定义了一个`get_book_info()`函数，用于从图书详情页中提取图书的详细信息。