介绍

是否苦于看漫画收费，那不如自己编个程序白嫖吧！

基本环境

python 3.6

pycharm

安装scrapy

pip install scrapy

创建scrapy项目

在命令行输入：

scrapy startproject 项目名称

创建爬虫文件

命令行输入：

scrapy genspider 爬虫文件名称 域名
注意：爬虫文件名称不能和项目名称一样
域名：比如https://www.baidu.com,baidu.com就是其域名

创建start文件

在spiders同级目录下创建start.py,写入：

from scrapy import cmdline

cmdline.execute('scrapy crawl 爬虫文件名称'.split())

目标url

本文介绍爬取漫画台的漫画.

QAQ,之前爬过一次，这次发现它url规则变了,不过没关系,逢山开路,遇水架桥

这里选取一剑独尊为例：

分析url规律

这里看到Google开发者工具elements-XHR-preview中返回的json数据，我们可以通过分析json数据爬取该漫画。

通过与其他url比对,发现只有chapter_newid部分是变化的,且上一话的url.request返回的json数据中包含了下一话的chapter_newid,如此一来url规律就分析好了.

提取数据

提取方法如下:

# 提取章节名称,url规则以及该章总共多少页
chapter_name = response.json()['data']['current_chapter']['chapter_name']
rule = response.json()['data']['current_chapter']['rule']
end_num = response.json()['data']['current_chapter']['end_num']

之后因为获取的url只是一部分规则,所以需要后续处理:

for num in range(1, end_num + 1):
	whole_url = origin + rule.replace('$$', str(num)) + '-mht.middle.webp'

整合爬虫文件

import scrapy
from ..items import ManhuataispiderItem


class ManhuataiSpider(scrapy.Spider):
    name = 'manhuatai'
    allowed_domains = ['manhuatai.com']

    start_urls = [
        'https://www.manhuatai.com/api/getchapterinfo?product_id=2&productname=mht&platformname=pc&comic_id=108393&chapter_newid=di1hua-1600506710013']

    def parse(self, response):
        # print(response.json())

        chapter_name = response.json()['data']['current_chapter']['chapter_name']
        rule = response.json()['data']['current_chapter']['rule']
        end_num = response.json()['data']['current_chapter']['end_num']
        # print(chapter_newid, chapter_name, rule, end_num)

        origin = 'https://mhpic.dm300.com'
        for num in range(1, end_num + 1):
            whole_url = origin + rule.replace('$$', str(num)) + '-mht.middle.webp'
            # print(whole_url)
            yield ManhuataispiderItem(img_url=whole_url, chapter_name=chapter_name, num=num)

        chapter_newid = response.json()['data']['next_chapter']['chapter_newid']
        print(chapter_newid)

        next_url = f'https://www.manhuatai.com/api/getchapterinfo?product_id=2&productname=mht&platformname=pc&comic_id=108393&chapter_newid={chapter_newid}'
        if chapter_newid:
            yield scrapy.Request(url=next_url, callback=self.parse)

请求头设置

请求头在middlewares文件中设置:

import faker


class HeadersDownloaderMiddleware:
    """headers中间件"""

    def process_request(self, request, spider):
        # 可以拿到请求体
        fake = faker.Faker()
        # request.headers  拿到请求头, 请求头是一个字典
        request.headers.update(
            {
                'user-agent': fake.user_agent(),
                'authority': 'www.manhuatai.com',
            }
        )
        return None

保持数据

保存数据在pipelines中保持,因为是二进制数据,所以需要重写:

from scrapy.pipelines.images import ImagesPipeline
import scrapy


# 二进制数据下载需要继承自 ImagesPipeline
class DownloadPicturePipeline(ImagesPipeline):
    """二进制数据的保存"""

    # get_media_requests  请求二进制数据的方法
    def get_media_requests(self, item, info):
        # 需要把二进制url提取出来
        img_url = item['img_url']
        # 构建二进制数据请求
        yield scrapy.Request(url=img_url)
	
    # file_path 定义文件保存路径
    def file_path(self, request, response=None, info=None, *, item=None):
        num = item['num']
        chapter_name = item['chapter_name']
        return f'{chapter_name}/{num}.jpg'

settings设置

1.  ROBOTSTXT_OBEY = False
   

2.  SPIDER_MIDDLEWARES = {
        'ManhuataiSpider.middlewares.HeadersDownloaderMiddleware': 543,
    }
   

3.  ITEM_PIPELINES = {
       'ManhuataiSpider.pipelines.DownloadPicturePipeline': 300,
    }
   

4.  IMAGES_STORE = './images'  # 在最后一定要添加,否则无法保存
   

运行

打开start.py文件,运行等待即可看到漫画被爬取了.