Python3爬虫基础练习

本文链接：https://blog.csdn.net/github_39655029/article/details/88534928

背景需求

完成作业的同时练习爬虫，利用Xpath匹配出需要爬取的内容；

需要爬取的新闻界面

需要爬取的信息

实现代码

代码语言：javascript复制

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time    : 2019/3/13 13:08
# @Author  : cunyu
# @Site    : cunyu1943.github.io
# @File    : NetaseNewsSpider.py
# @Software: PyCharm

import requests
from lxml import etree
import xlwt


headers = {
	"User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.75 Safari/537.36"
}

# 根据url获取刚网页中的新闻详情页的网址列表
def getNewsDetailUrlList(url):
	"""
	:param url: 每页的URL
	:return newDetailList:每页包含的新闻详情URL
	"""
	response = requests.get(url, headers=headers)
	html = response.content.decode('gbk')
	selector = etree.HTML(html)
	newsDetailList = selector.xpath('//ul[@id="news-flow-content"]//li//div[@class="titleBar clearfix"]//h3//a/@href')
	return newsDetailList


# 获取新闻标题
def getNewsTitle(detailUrl):
	"""
	:param detailUrl:新闻详情url
	:return newsTitle:新闻标题
	"""
	response = requests.get(detailUrl, headers=headers)
	html = response.content.decode('gbk')
	selector = etree.HTML(html)
	newsTitle = selector.xpath('//div[@class="post_content_main"]//h1/text()')
	return newsTitle


# 获取新闻详情内容
def getNewsContent(detailUrl):
	"""
	:param detailUrl: 新闻详情url
	:return newsContent: 新闻内容详情
	"""
	response = requests.get(detailUrl, headers=headers)
	html = response.content.decode('gbk')
	selector = etree.HTML(html)
	newsContent = selector.xpath('//div[@class="post_text"]//p/text()')
	return newsContent

# 将新闻标题和内容写入文件
	TODO

# 获取翻页网址列表
def getUrlList(baseUrl, num):
	"""
	:param baseUrl:基础网址
	:param num: 翻到第几页
	:return urlList: 翻页网址列表
	"""
	urlList = []
	urlList.append(baseUrl)
	for i in range(2, num 1):
		urlList.append(baseUrl   "_"   str(i).zfill(2))
	return urlList

if __name__ == '__main__':
	baseUrl = "http://tech.163.com/special/gd2016"
	num = int(input('输入你要爬取的页数: '))
	urlList = getUrlList(baseUrl, num)

	print(urlList)
	detailUrl = []
	for url in urlList:
		for i in getNewsDetailUrlList(url):
			detailUrl.append(i)
	print(detailUrl)


	print(getNewsTitle(detailUrl[0]))
	print(getNewsContent(detailUrl[0]))

	# # 将爬取的文本存入文本文件
	# with open('news.txt', 'w', encoding='utf-8') as f, open('newsTitle.txt', 'w', encoding='utf-8') as titleFile,
	# 		open('newsContent.txt', 'w', encoding='utf-8') as contentFile:
	# 	print('正在爬取中。。。')
	# 	for i in detailUrl:
	# 		f.write(''.join(getNewsTitle(i)))
	# 		f.write('n')
	# 		f.write(''.join(getNewsContent(i)))
	# 		f.write('n')
	# 
	# 		titleFile.write(''.join(getNewsTitle(i)))
	# 		titleFile.write('n')
	# 
	# 		contentFile.write(''.join(getNewsContent(i)))
	# 		contentFile.write('n')
	# 
	# print('文件写入成功')

	# 将爬取得文本存入excel文件
	# 创建一个Excel文件
	workbook = xlwt.Workbook(encoding='utf-8')

	news_sheet = workbook.add_sheet('news')

	news_sheet.write(0, 0, 'Title')
	news_sheet.write(0, 1, 'Content')
	print('正在爬取中。。。')
	for i in range(len(detailUrl)):
		# print(detailUrl[i])
		news_sheet.write(i   1, 0, getNewsTitle(detailUrl[i]))
		news_sheet.write(i   1, 1, getNewsContent(detailUrl[i]))

	# 将写入操作保存到指定Excel文件中
	workbook.save('网易新闻.xls')
	print('文件写入成功')

结果

代码运行结果

保存的文件

总结

总体来说比较简单，代码也存在需要改进的地方，后续会改进更新，有其他想法的也可以相互交流！

爬虫 xpath

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