前情提要:
一:scrapy 爬取妹子网 全站
知识点: scrapy回调函数的使用
二: scrapy的各个组件之间的关系解析
Scrapy 框架
Scrapy是用纯Python实现一个为了爬取网站数据、提取结构性数据而编写的应用框架，用途非常广泛。
框架的力量，用户只需要定制开发几个模块就可以轻松的实现一个爬虫，用来抓取网页内容以及各种图片，非常之方便。
Scrapy 使用了 Twisted'twɪstɪd异步网络框架来处理网络通讯，可以加快我们的下载速度，不用自己去实现异步框架，并且包含了各种中间件接口，可以灵活的完成各种需求。
三:post 的scrapy的使用
四:首页详情页的数据连续爬取
4.1:setting设置 ,
注意:设置
->1:
这里我们不遵守机器人协议。
代码语言：javascript复制# -*- coding: utf-8 -*-
# Scrapy settings for postdemo1 project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
# https://doc.scrapy.org/en/latest/topics/settings.html
# https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
# https://doc.scrapy.org/en/latest/topics/spider-middleware.html
BOT_NAME = 'postdemo1'
SPIDER_MODULES = ['postdemo1.spiders']
NEWSPIDER_MODULE = 'postdemo1.spiders'
# Crawl responsibly by identifying yourself (and your website) on the user-agent
USER_AGENT = 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36'
# Obey robots.txt rules
# 不遵循robot协议
ROBOTSTXT_OBEY = False
# 设置错误等级
# LOG_LEVEL ='ERROR'
# Configure maximum concurrent requests performed by Scrapy (default: 16)
#CONCURRENT_REQUESTS = 32
# Configure a delay for requests for the same website (default: 0)
# See https://doc.scrapy.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
#DOWNLOAD_DELAY = 3
# The download delay setting will honor only one of:
#CONCURRENT_REQUESTS_PER_DOMAIN = 16
#CONCURRENT_REQUESTS_PER_IP = 16
# Disable cookies (enabled by default)
#COOKIES_ENABLED = False
# Disable Telnet Console (enabled by default)
#TELNETCONSOLE_ENABLED = False
# Override the default request headers:
#DEFAULT_REQUEST_HEADERS = {
# 'Accept': 'text/html,application/xhtml xml,application/xml;q=0.9,*/*;q=0.8',
# 'Accept-Language': 'en',
#}
# Enable or disable spider middlewares
# See https://doc.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
# 'postdemo1.middlewares.Postdemo1SpiderMiddleware': 543,
#}
# Enable or disable downloader middlewares
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES = {
# 'postdemo1.middlewares.Postdemo1DownloaderMiddleware': 543,
#}
# Enable or disable extensions
# See https://doc.scrapy.org/en/latest/topics/extensions.html
#EXTENSIONS = {
# 'scrapy.extensions.telnet.TelnetConsole': None,
#}
# Configure item pipelines
# See https://doc.scrapy.org/en/latest/topics/item-pipeline.html
#ITEM_PIPELINES = {
# 'postdemo1.pipelines.Postdemo1Pipeline': 300,
#}
# Enable and configure the AutoThrottle extension (disabled by default)
# See https://doc.scrapy.org/en/latest/topics/autothrottle.html
#AUTOTHROTTLE_ENABLED = True
# The initial download delay
#AUTOTHROTTLE_START_DELAY = 5
# The maximum download delay to be set in case of high latencies
#AUTOTHROTTLE_MAX_DELAY = 60
# The average number of requests Scrapy should be sending in parallel to
# each remote server
#AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0
# Enable showing throttling stats for every response received:
#AUTOTHROTTLE_DEBUG = False
# Enable and configure HTTP caching (disabled by default)
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
#HTTPCACHE_ENABLED = True
#HTTPCACHE_EXPIRATION_SECS = 0
#HTTPCACHE_DIR = 'httpcache'
#HTTPCACHE_IGNORE_HTTP_CODES = []
#HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'4.2 爬虫文件
1:爬取首页
2:爬取详情页
4.3数据持久化
代码语言：javascript复制# -*- coding: utf-8 -*-
# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: https://doc.scrapy.org/en/latest/topics/item-pipeline.html
# class Postdemo1Pipeline(object):
# def process_item(self, item, spider):
# print(item)
# return item
import pymysql
from redis import Redis
class Postdemo1Pipeline(object):
fp = None
def open_spider(self,spider):
print('开始爬虫！')
self.fp = open('./xiaohua.txt','w',encoding='utf-8')
#作用：实现持久化存储的操作
#该方法的item参数就可以接收爬虫文件提交过来的item对象
#该方法每接收一个item就会被调用一次（调用多次）
def process_item(self, item, spider):
name = item['name']
desc = item['desc']
self.fp.write(name ':' desc 'n')
#返回值的作用：就是将item传递给下一个即将被执行的管道类
return item
def close_spider(self,spider):
print('结束爬虫！')
self.fp.close()
class MysqlPipeline(object):
conn = None
cursor = None
def open_spider(self, spider):
#解决数据库字段无法存储中文处理：alter table tableName convert to charset utf8;
self.conn = pymysql.Connect(host='127.0.0.1',port=3306,user='root',password='123',db='test')
print(self.conn)
def process_item(self, item, spider):
self.cursor = self.conn.cursor()
try:
self.cursor.execute('insert into xiahua values ("%s","%s")'%(item['name'],item['img_url']))
self.conn.commit()
except Exception as e:
print(e)
self.conn.rollback()
return item
def close_spider(self, spider):
self.cursor.close()
self.conn.close()
class RedisPipeline(object):
conn = None
def open_spider(self, spider):
self.conn = Redis(host='127.0.0.1',port=6379)
print(self.conn)
def process_item(self, item, spider):
dic = {
'name':item['name'],
'img_url':item['img_url']
}
print(dic)
self.conn.lpush('xiaohua',dic)
return item
def close_spider(self, spider):
pass以上只是提供思路。可以把这个网站妹子图片爬取下来。
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