爬虫程序举例分析怎么写

时间:2025-01-27 17:01:19 单机游戏

爬虫程序举例分析可以从以下几个方面进行:

基础爬虫示例

使用`requests`库发送HTTP请求,获取网页内容并打印出来。

示例代码如下:

```python

import requests

url = 'https://example.com'

response = requests.get(url)

print(response.text)

```

模拟浏览器行为

为了避免被网站识别为非法爬虫,可以添加请求头信息,模拟浏览器的行为。

示例代码如下:

```python

import requests

url = 'https://example.com'

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'

}

response = requests.get(url, headers=headers)

print(response.text)

```

使用BeautifulSoup解析HTML内容

使用`BeautifulSoup`库解析HTML内容,提取所需数据。

示例代码如下:

```python

import requests

from bs4 import BeautifulSoup

url = 'https://example.com'

response = requests.get(url)

soup = BeautifulSoup(response.text, 'html.parser')

title = soup.title.string

print(title)

```

使用XPath提取数据

使用XPath选择器提取HTML中的数据。

示例代码如下:

```python

import requests

from lxml import etree

url = 'https://nba.hupu.com/stats/players'

headers = {

"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36"

}

res = requests.get(url=url, headers=headers)

e = etree.HTML(res.text)

player = e.xpath('//*[@id="data_js"]/div/div/table/tbody/tr/td/a/text()')

team = e.xpath('//*[@id="data_js"]/div/div/table/tbody/tr/td/a/text()')

hit_rate = e.xpath('//*[@id="data_js"]/div/div/table/tbody/tr/td/text()')[1:]

score = e.xpath('//*[@id="data_js"]/div/div/table/tbody/tr/td/text()')[1:]

for p, t, hr, s in zip(player, team, hit_rate, score):

print(f"Player: {p}, Team: {t}, Hit Rate: {hr}, Score: {s}")

```

多线程爬虫

使用多线程提高爬虫的效率。

示例代码如下:

```python

import requests

import re

import time

def main(page):

url = f'https://tieba.baidu.com/p/page/{page}'

response = requests.get(url)

content = response.text

comments = re.findall(r'.*?', content, re.S)

with open('comments.csv', 'a', encoding='utf-8', newline='') as f:

csvwriter = csv.writer(f)

csvwriter.writerow(['Comment', 'User', 'Time'])

for comment in comments:

match = re.search(r'([^<]+)', comment)

if match:

csvwriter.writerow([comment, match.group(1), time.strftime('%Y-%m-%d %H:%M:%S')])

for page in range(1, 8):

main(page)

time.sleep(2)

```

爬虫框架示例

使用爬虫框架(如Scrapy)进行更复杂的爬虫开发。

示例代码如下: