url_list = ['http://www.xbiquge.la' + x for x in html.xpath('//div[@id="list"]/dl/dd/a/@href')]怎么理解
时间: 2023-12-15 09:03:34 浏览: 24
这段代码的作用是根据给定的XPath表达式,从HTML页面中获取一组URL链接,并将每个链接拼接到"http://www.xbiquge.la"的前面。具体的解析过程如下:
1. `html.xpath('//div[@id="list"]/dl/dd/a/@href')`:使用XPath表达式`//div[@id="list"]/dl/dd/a/@href`在HTML页面中定位到所有`<a>`标签的`href`属性。
2. `['http://www.xbiquge.la' + x for x in ...]`:对于定位到的每个`href`属性值,通过列表推导式将其前面添加"http://www.xbiquge.la",形成完整的URL链接。
3. 最终得到的`url_list`是包含所有完整URL链接的列表。
请注意,这是一段Python代码,它利用XPath和列表推导式来解析HTML页面并生成URL链接列表。
相关问题
for i in range(1,123): if i == 1: url = 'https://www.4399.com/flash_fl/5_1.htm' html = requests.get(url,headers=headers).content doc = etree.HTML(html) name = doc.xpath('//*[@class="list affix cf"]/li/a/text()') url_1 = doc.xpath('//*[@class="list affix cf"]/li/a/@href') data_list = [] for wu_y_s in url_1: new_url = 'https://www.4399.com' +wu_y_s for i in range(len(name)): dit = {} dit['游戏名称'] = name[i] dit['游戏地址'] = new_url[i] data_list.append(dit) csv_writer.writerow(dit) else: url = 'https://www.4399.com/flash_fl/more_5_{}.htm'.format(str(i)) html = requests.get(url,headers=headers).content doc = etree.HTML(html) name = doc.xpath('//*[@class="list affix cf"]/li/a/text()') url_1 = doc.xpath('//*[@class="list affix cf"]/li/a/@href') data_list = [] for wu_y_s in url_1: new_url = 'https://www.4399.com' +wu_y_s for i in range(len(name)): dit = {} dit['游戏名称'] = name[i] dit['游戏地址'] = new_url[i] data_list.append(dit) csv_writer.writerow(dit) print(data_list)怎么改
根据你的代码,你想爬取4399游戏网站的游戏名称和链接,并将其保存到CSV文件中。但是,你的代码有一些问题,其中最主要的问题在于每次循环都会覆盖之前爬取到的数据,最终只会保存最后一页数据。
为了解决这个问题,你需要将data_list定义在循环外部,这样在每次循环中都会将新爬取到的数据添加到data_list中。另外,还需要修改CSV文件的写入方式,应该在循环结束后再次打开CSV文件并写入所有数据。
下面是修改后的代码示例:
```
import requests
import csv
from lxml import etree
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'}
data_list = [] # 定义空列表,用于保存所有数据
for i in range(1, 123):
if i == 1:
url = 'https://www.4399.com/flash_fl/5_1.htm'
else:
url = 'https://www.4399.com/flash_fl/more_5_{}.htm'.format(str(i))
html = requests.get(url, headers=headers).content
doc = etree.HTML(html)
name = doc.xpath('//*[@class="list affix cf"]/li/a/text()')
url_1 = doc.xpath('//*[@class="list affix cf"]/li/a/@href')
for wu_y_s in url_1:
new_url = 'https://www.4399.com' + wu_y_s
for i in range(len(name)):
dit = {}
dit['游戏名称'] = name[i]
dit['游戏地址'] = new_url
data_list.append(dit)
# 将数据写入CSV文件
with open('4399_games.csv', 'w', newline='', encoding='utf-8') as f:
fieldnames = ['游戏名称', '游戏地址']
csv_writer = csv.DictWriter(f, fieldnames=fieldnames)
csv_writer.writeheader()
csv_writer.writerows(data_list)
print(data_list)
```
在上面的代码中,首先定义了一个空列表data_list,然后在每次循环中将新爬取到的数据添加到data_list中。在所有循环结束后,再次打开CSV文件并写入所有数据。最终,data_list中保存了所有游戏名称和链接的字典数据,并且已经成功写入到CSV文件中。
import requests from lxml import etree import csv headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36' } f = open('4399益智副本2.csv', mode='w', encoding='utf-8-sig', newline='') csv_writer = csv.DictWriter(f, fieldnames=[ '游戏地址','游戏名称']) csv_writer.writeheader() for i in range(1,124): if i == 1: url = 'https://www.4399.com/flash_fl/5_1.htm' html = requests.get(url,headers=headers).content doc = etree.HTML(html) id = doc.xpath('//*[@id="classic"]/li/a/@href') name = doc.xpath('//*[@id="classic"]/li/a/text()') url_1 = 'https://www.4399.com'+id data_list = [] for i in range(len(name)): dit = {} dit['游戏地址'] = url_1[i] dit['游戏名称'] = name[i] data_list.append(dit) csv_writer.writerow(dit) else: url = 'https://www.4399.com/flash_fl/more_5_{}.htm'.format(str(i)) html = requests.get(url,headers=headers).content doc = etree.HTML(html) id = doc.xpath('//*[@id="classic"]/li/a/@href') name = doc.xpath('//*[@id="classic"]/li/a/text()') url_1 = 'https://www.4399.com'+id data_list = [] for i in range(len(name)): dit = {} dit['游戏地址'] = url_1[i] dit['游戏名称'] = name[i] data_list.append(dit) csv_writer.writerow(dit) print(data_list)这个摆错怎么改
你的代码中存在一个问题,即在第15行中,你将 `id` 变量赋值为一个列表,而不是单个链接。因此,你需要将其改为 `id[i]`:
```
url_1 = 'https://www.4399.com' + id[i]
```
另外,你也需要将 `csv_writer.writerow(dit)` 放在 for 循环外面,否则你在每次循环中都会写入一行,导致重复写入。
下面是修改后的代码:
```
import requests
from lxml import etree
import csv
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36'
}
f = open('4399益智副本2.csv', mode='w', encoding='utf-8-sig', newline='')
csv_writer = csv.DictWriter(f, fieldnames=['游戏地址', '游戏名称'])
csv_writer.writeheader()
for i in range(1, 124):
if i == 1:
url = 'https://www.4399.com/flash_fl/5_1.htm'
else:
url = 'https://www.4399.com/flash_fl/more_5_{}.htm'.format(str(i))
html = requests.get(url, headers=headers).content
doc = etree.HTML(html)
id = doc.xpath('//*[@id="classic"]/li/a/@href')
name = doc.xpath('//*[@id="classic"]/li/a/text()')
data_list = []
for i in range(len(name)):
dit = {}
dit['游戏地址'] = 'https://www.4399.com' + id[i]
dit['游戏名称'] = name[i]
data_list.append(dit)
csv_writer.writerows(data_list)
print(data_list)
f.close()
```