一、sprapy爬虫框架
pip install pypiwin32
1) 创建爬虫框架
scrapy startproject Project # 创建爬虫项目
You can start your first spider with:
cd Project
scrapy genspider example example.com
cd Project # 进入项目
scrapy genspider chouti chouti.com # 创建爬虫
创建爬虫框架
2）执行爬虫
class ChoutiSpider(scrapy.Spider):
name = 'chouti'
allowed_domains = ['chouti.com']
# start_urls = ['http://dig.chouti.com/'] #
start_urls = ['http://www.autohome.com.cn/news'] def parse(self, response):
# response 访问网页的后的返回值
print(response) # < https://www.autohome.com.cn/news/>
print(response.url) # https://www.autohome.com.cn/news/
爬虫文件编写
（debug模式）
scrapy --help 参数帮助
pip install pypiwin32 # 执行爬虫的依赖包
scrapy crawl chouti # 执行爬虫,查看经过的中间键 # 常用执行爬虫操作
scrapy crawl chouti --nolog # 执行爬虫
执行爬虫命令
3）处理显示编码
import scrapy import sys
import io
sys.stdout = io.TextIOWrapper(sys.stdout.buffer,encoding='gb18030') # 处理显示编码 class ChoutiSpider(scrapy.Spider):
......... def parse(self, response):
content = str(response.body,encoding='utf-8')
print(content)
编码
4.1）寻找标签：from scrapy.selector import Selector,HtmlXPathSelector
class ChoutiSpider(scrapy.Spider):
name = 'chouti'
allowed_domains = ['chouti.com']
# start_urls = ['http://dig.chouti.com/']
start_urls = ['http://www.autohome.com.cn/news'] def parse(self, response):
'''
# # response 访问网页的后的返回值
# print(response) # < https://www.autohome.com.cn/news/>
# # 查看访问的地址
# print(response.url) # https://www.autohome.com.cn/news/
# 获取到网页文本代码
# print(response.text) # 网页代码
print(response.body)
''' # 第一种 找到整个文档所有的 a 便签
# hax = Selector(response=response).xpath('//a') # 标签对象列表
# for i in hax:
# print(i) # 便签对象 # 第二种 找到所有的div标签且属性是 id="content-list"
# hax = Selector(response=response).xpath('//div[@id="content-list"]').extract() # 拿到便签非标签对象 # 第三种 找到所有的div标签且属性是 id="content-list"，并寻找它的儿子标签 （/)
# hxs = Selector(response=response).xpath('//div[@id="content-list"]/div[@class="item"]').extract() # 标签对象转换成字符串
# for i in hxs:
# print(i) # 第四种 找到所有的div标签且属性是 id="content-list"，并寻找它的儿子标签 （/)
hxs = Selector(response=response).xpath('//div[@id="content-list"]/div[@class="item"]')
for obj in hxs:
# 在当前标签下取所有的a 标签 .//a
a = obj.xpath('.//a[@class="show-content"]/text()').extract()
# a = obj.xpath('.//a[@class="show-content"]/text()').extract_first() # 拿列表的第一个
# print(a)
print(a.strip()) # 去除空白
寻找标签
常用标签寻找总结
// 表示子孙中
.// 当前对象的子孙中
/ 儿子
/div 儿子中的div标签
/div[@id="i1"] 儿子中的div标签且id=i1
/div[@id="i1"] 儿子中的div标签且id=i1
obj.extract() # 列表中的每一个对象转换字符串 =》 []
obj.extract_first() # 列表中的每一个对象转换字符串 => 列表第一个元素
//div/text() 获取某个标签的文本
hax = Selector(response=response).xpath('//div[@id="dig_lepage"]//a/text()') # 拿内容
hax = Selector(response=response).xpath('//div[@id="dig_lepage"]//a/@href') # 拿标签属性
# starts-with(@href, "/all/hot/recent/ 以什么开头
hax = Selector(response=response).xpath('//a[starts-with(@href, "/all/hot/recent/")]/@href').extract()
# 正则取
hxs2 = Selector(response=response).xpath('//a[re:test(@href, "/all/hot/recent/\d+")]/@href').extract()
print(response.meta) 查询寻找深度
4.2）所有选择器示例归纳
response = HtmlResponse(url='http://example.com', body=html,encoding='utf-8')
# hxs = HtmlXPathSelector(response)
# print(hxs)
# hxs = Selector(response=response).xpath('//a')
# print(hxs)
# hxs = Selector(response=response).xpath('//a[2]')
# print(hxs)
# hxs = Selector(response=response).xpath('//a[@id]')
# print(hxs)
# hxs = Selector(response=response).xpath('//a[@id="i1"]')
# print(hxs)
# hxs = Selector(response=response).xpath('//a[@href="link.html"][@id="i1"]')
# print(hxs)
# hxs = Selector(response=response).xpath('//a[contains(@href, "link")]')
# print(hxs)
# hxs = Selector(response=response).xpath('//a[starts-with(@href, "link")]')
# print(hxs)
# hxs = Selector(response=response).xpath('//a[re:test(@id, "i\d+")]')
# print(hxs)
# hxs = Selector(response=response).xpath('//a[re:test(@id, "i\d+")]/text()').extract()
# print(hxs)
# hxs = Selector(response=response).xpath('//a[re:test(@id, "i\d+")]/@href').extract()
# print(hxs)
# hxs = Selector(response=response).xpath('/html/body/ul/li/a/@href').extract()
# print(hxs)
# hxs = Selector(response=response).xpath('//body/ul/li/a/@href').extract_first()
# print(hxs) # ul_list = Selector(response=response).xpath('//body/ul/li')
# for item in ul_list:
# v = item.xpath('./a/span')
# # 或
# # v = item.xpath('a/span')
# # 或
# # v = item.xpath('*/a/span')
# print(v)
选择器示例
5.1）获取当前页的所有页面，即a 标签的href属性内容
class ChoutiSpider(scrapy.Spider):
name = 'chouti'
allowed_domains = ['chouti.com']
# start_urls = ['http://dig.chouti.com/']
start_urls = ['http://www.autohome.com.cn/news'] visited_urls = set()
def parse(self, response):
# 获取当前页的所有页码
'''
hax = Selector(response=response).xpath('//div[@id="dig_lepage"]//a/@href').extract()
for item in hax:
print(item) # 可能有重复的页面
'''
hax = Selector(response=response).xpath('//div[@id="dig_lepage"]//a/@href').extract()
for item in hax:
if item in self.visited_urls:
print('已经存在')
else:
self.visited_urls.add(item)
print(item)
对url内容加密保存
class ChoutiSpider(scrapy.Spider):
name = 'chouti'
allowed_domains = ['chouti.com']
# start_urls = ['http://dig.chouti.com/']
start_urls = ['http://www.autohome.com.cn/news'] visited_urls = set()
def parse(self, response):
hax = Selector(response=response).xpath('//div[@id="dig_lepage"]//a/@href').extract()
for url in hax:
md5_url = self.md5(url)
if url in self.visited_urls:
print('已经存在')
else:
self.visited_urls.add(md5_url)
print(url) def md5(self,url):
import hashlib
obj = hashlib.md5()
obj.update(bytes(url,encoding='utf-8'))
return obj.hexdigest()
5.2）获取该网站的所有页面
# -*- coding: utf- -*-
import scrapy
from scrapy.selector import Selector,HtmlXPathSelector
from scrapy.http import Request
import sys
import io
sys.stdout = io.TextIOWrapper(sys.stdout.buffer,encoding='gb18030') # 处理显示编码 class ChoutiSpider(scrapy.Spider):
name = 'chouti'
allowed_domains = ['chouti.com']
# start_urls = ['http://dig.chouti.com/']
start_urls = ['http://www.autohome.com.cn/news'] visited_urls = set()
def parse(self, response):
hax = Selector(response=response).xpath('//a[starts-with(@href, "/all/hot/recent/")]/@href').extract()
for url in hax:
md5_url = self.md5(url)
if url in self.visited_urls:
pass
else:
print(url)
self.visited_urls.add(md5_url)
url = "http://dig.chouti.com%s" %url
# 将新要访问的url添加到调度器
yield Request(url=url,callback=self.parse) def md5(self,url):
import hashlib
obj = hashlib.md5()
obj.update(bytes(url,encoding='utf-8'))
return obj.hexdigest()
5.3）设置访问深度，即不获取到所有的页面，递归寻找的层数
#配置文件最后写入
DEPIH_LIMIT =
setting.py
6）数据保存操作
配置文件取消注释pipeline
ITEM_PIPELINES = {
'Project.pipelines.ProjectPipeline': ,
}
settings.py
定义保存的数据类字段名
class ChoutiItem(scrapy.Item):
# define the fields for your item here like:
# name = scrapy.Field()
title = scrapy.Field()
href = scrapy.Field()
items.py
将获取的对象传递给pipelines进行持久化保存
def parse(self, response):
hxs1 = Selector(response=response).xpath('//div[@id="content-list"]/div[@class="item"]') # 标签对象列表
for obj in hxs1:
title = obj.xpath('.//a[@class="show-content"]/text()').extract_first().strip()
href = obj.xpath('.//a[@class="show-content"]/@href').extract_first().strip()
item_obj = ChoutiItem(title=title,href=href)
# 将item 对象传递给pipeline
yield item_obj
6.1）写入文件
class ProjectPipeline(object):
def process_item(self, item, spider):
print(spider,item)
tpl = "%s\n%s\n\n" %(item['item'],item['href'])
f = open('news.json','a')
f.write(tpl)
f.close()
pipeline.py
7）知识小结
命令：
scrapy startproject xxx
cd xxx
scrapy genspider name name.com
scrapy crawl name
编写代码：
a. name不能省略
b. start_urls,起始URL地址
c. allowed_domains = ["chouti.com"] 允许的域名
d. 重写start_requests，指定初始处理请求的函数
def start_requests(self):
for url in self.start_urls:
yield Request(url,callback=self.parse1)
e. 响应response
repsonse.url
repsonse.text
repsonse.body
response.meta = {'depth': ‘深度’} f. 采集数据 Selector(response=response).xpath()
//div
//div[@id="i1"]
//div[starts-with(@id,"i1")]
//div[re:test(@id,"i1")]
//div/a
#
obj.xpath('./')
obj.xpath('.//') //div/a/text()
//div/a/@href Selector().extract()
Selector().extract_first() //a[@id]
//a/@id g. yield Request(url='',callback='xx') h. yield Item(name='xx',titile='xxx') i. pipeline class Foo:
def process_item(self,item,spider):
.... settings = {
"xx.xx.xxx.Foo1": , # 谁小谁先执行
"xx.xx.xxx.Foo2": ,
}
知识点小结
二、scrapy框架知识补充
from scrapy.dupefilter import RFPDupeFilter # 查看去重的url源代码，在编写自己的
1）自定义类，url去重，内容保存方式
class RepeatFilter(object):
def __init__(self):
#
self.visited_set = set()
@classmethod
def from_settings(cls, settings):
#
return cls() def request_seen(self, request):
#
if request.url in self.visited_set:
return True
self.visited_set.add(request.url)
return False def open(self): # can return deferred
#
# print('open')
pass def close(self, reason): # can return a deferred
#
# print('close')
pass
def log(self, request, spider): # log that a request has been filtered
# print('log....')
pass
duplication.py
配置文件引入自定义类
DUPEFILTER_CLASS = "day96.duplication.RepeatFilter" # 自定义的
# DUPEFILTER_CLASS = "scrapy.dupefilters.RFPDupeFilter" # scrapy框架自带的
配置文件引用自定义类
主逻辑文件调用回调函数
class ChoutiSpider(scrapy.Spider):
name = 'chouti'
allowed_domains = ['chouti.com']
# start_urls = ['http://dig.chouti.com/']
start_urls = ['http://www.autohome.com.cn/news'] def parse(self, response):
hax2 = Selector(response=response).xpath('//a[starts-with(@href, "/all/hot/recent/")]/@href').extract()
for url in hax2:
url = "http://dig.chouti.com%s" %url
yield Request(url=url,callback=self.parse)
chouti.py
2.1）pipelines数据库持久化补充（分工明细）
class ProjectPipeline(object):
def __init__(self,conn_str):
# 数据的初始化
self.conn_str = conn_str @classmethod
def from_crawler(cls, crawler):
"""
初始化时候，用于创建pipeline对象,读取配置文件
:param crawler:
:return:
"""
conn_str = crawler.settings.get('DB')
return cls(conn_str) def open_spider(self,spider):
"""
爬虫开始执行时，调用
:param spider:
:return:
"""
print('')
self.conn = open(self.conn_str,'a') def close_spider(self,spider):
"""
爬虫关闭时，被调用
:param spider:
:return:
"""
print('')
self.conn.close() def process_item(self, item, spider):
# 每当数据需要持久化时，就需要被调用
# if spider.name == "chouti":
tpl = "%s\n%s\n\n" %(item['item'],item['href'])
self.conn.write(tpl)
pipelines.py
2.2）如果有多个pipelines时，是否考虑让下一个执行
配置文件配置pipelines。根据执行顺序考虑谁先谁后
ITEM_PIPELINES = {
'day96.pipelines.Day96Pipeline': ,
'day96.pipelines.Day97Pipeline': ,
}
settings.py
from scrapy.exceptions import DropItem
根据返回值决定是否交给下一个pipelines执行
class ProjectPipeline(object):
def __init__(self,conn_str):
# 数据的初始化
self.conn_str = conn_str @classmethod
def from_crawler(cls, crawler):
"""
初始化时候，用于创建pipeline对象,读取配置文件
:param crawler:
:return:
"""
conn_str = crawler.settings.get('DB')
return cls(conn_str) def open_spider(self,spider):
"""
爬虫开始执行时，调用
:param spider:
:return:
"""
print('')
self.conn = open(self.conn_str,'a') def close_spider(self,spider):
"""
爬虫关闭时，被调用
:param spider:
:return:
"""
print('')
self.conn.close() def process_item(self, item, spider):
# 每当数据需要持久化时，就需要被调用
# if spider.name == "chouti":
tpl = "%s\n%s\n\n" %(item['item'],item['href'])
self.conn.write(tpl)
# 交给下一个pipeline处理
return item
# 丢弃item,不交给下一个pipeline处理
# raise DropItem() class ProjectPipeline2(object):
pass
return item 或 DropItem()
2.3）pipelines总结
pipeline补充
from scrapy.exceptions import DropItem
class Day96Pipeline(object): def __init__(self,conn_str):
self.conn_str = conn_str @classmethod
def from_crawler(cls, crawler):
"""
初始化时候，用于创建pipeline对象
:param crawler:
:return:
"""
conn_str = crawler.settings.get('DB')
return cls(conn_str) def open_spider(self,spider):
"""
爬虫开始执行时，调用
:param spider:
:return:
"""
self.conn = open(self.conn_str, 'a') def close_spider(self,spider):
"""
爬虫关闭时，被调用
:param spider:
:return:
"""
self.conn.close() def process_item(self, item, spider):
"""
每当数据需要持久化时，就会被调用
:param item:
:param spider:
:return:
"""
# if spider.name == 'chouti'
tpl = "%s\n%s\n\n" %(item['title'],item['href'])
self.conn.write(tpl)
# 交给下一个pipeline处理
return item
# 丢弃item，不交给
# raise DropItem() """
4个方法
crawler.settings.get('setting中的配置文件名称且必须大写')
process_item方法中，如果抛出异常DropItem表示终止，否则继续交给后续的pipeline处理
spider进行判断
"""
pipelines总结
3.1）使用cookie登录抽屉，验证是否成功
from scrapy.http.cookies import CookieJar 导入cookies模块
# -*- coding: utf- -*-
import scrapy
import sys
import io
from scrapy.http import Request
from scrapy.selector import Selector, HtmlXPathSelector
from ..items import ChoutiItem sys.stdout = io.TextIOWrapper(sys.stdout.buffer,encoding='gb18030')
from scrapy.http.cookies import CookieJar class ChoutiSpider(scrapy.Spider):
name = "chouti"
allowed_domains = ["chouti.com",]
start_urls = ['http://dig.chouti.com/'] def parse(self, response):
cookie_obj = CookieJar()
cookie_obj.extract_cookies(response,response.request)
# print(cookie_obj._cookies) # 查看cookie # 带上用户名密码+cookie
yield Request(
url="http://dig.chouti.com/login",
method='POST',
body = "phone=8615331254089&password=woshiniba&oneMonth=1",
headers={'Content-Type': "application/x-www-form-urlencoded; charset=UTF-8"},
cookies=cookie_obj._cookies,
callback=self.check_login
) def check_login(self,response):
print(response.text) # 验证是否登录成功
chouti.py
登录成功的信息
3.2）首页的当前页点赞
import scrapy
import sys
import io
from scrapy.http import Request
from scrapy.selector import Selector, HtmlXPathSelector
from ..items import ChoutiItem sys.stdout = io.TextIOWrapper(sys.stdout.buffer,encoding='gb18030')
from scrapy.http.cookies import CookieJar class ChoutiSpider(scrapy.Spider):
name = "chouti"
allowed_domains = ["chouti.com",]
start_urls = ['http://dig.chouti.com/'] cookie_dict = None
def parse(self, response):
cookie_obj = CookieJar()
cookie_obj.extract_cookies(response,response.request)
# print(cookie_obj._cookies) # 查看cookie
self.cookie_dict = cookie_obj._cookies
# 带上用户名密码+cookie
yield Request(
url="http://dig.chouti.com/login",
method='POST',
body = "phone=8615331254089&password=woshiniba&oneMonth=1",
headers={'Content-Type': "application/x-www-form-urlencoded; charset=UTF-8"},
cookies=cookie_obj._cookies,
callback=self.check_login
) def check_login(self,response):
print(response.text) # 验证是否登录成功
# 如果成功
yield Request(url="http://dig.chouti.com/",callback=self.good) def good(self,response):
id_list = Selector(response=response).xpath('//div[@share-linkid]/@share-linkid').extract()
for nid in id_list:
print(nid)
url = "http://dig.chouti.com/link/vote?linksId=%s" % nid
yield Request(
url=url,
method="POST",
cookies=self.cookie_dict,
callback=self.show # 对发送点赞请求的返回数据
) def show(self,response):
# 查看是否点赞成功
print(response.text)
chouti.py
3.3）为所有的页面点赞
# -*- coding: utf- -*-
import scrapy
import sys
import io
from scrapy.http import Request
from scrapy.selector import Selector, HtmlXPathSelector
from ..items import ChoutiItem sys.stdout = io.TextIOWrapper(sys.stdout.buffer,encoding='gb18030')
from scrapy.http.cookies import CookieJar class ChoutiSpider(scrapy.Spider):
name = "chouti"
allowed_domains = ["chouti.com",]
start_urls = ['http://dig.chouti.com/'] cookie_dict = None
def parse(self, response):
cookie_obj = CookieJar()
cookie_obj.extract_cookies(response,response.request)
# print(cookie_obj._cookies) # 查看cookie
self.cookie_dict = cookie_obj._cookies
# 带上用户名密码+cookie
yield Request(
url="http://dig.chouti.com/login",
method='POST',
body = "phone=8615331254089&password=woshiniba&oneMonth=1",
headers={'Content-Type': "application/x-www-form-urlencoded; charset=UTF-8"},
cookies=cookie_obj._cookies,
callback=self.check_login
) def check_login(self,response):
print(response.text) # 验证是否登录成功
# 如果成功
yield Request(url="http://dig.chouti.com/",callback=self.good) def good(self,response):
id_list = Selector(response=response).xpath('//div[@share-linkid]/@share-linkid').extract()
for nid in id_list:
print(nid)
url = "http://dig.chouti.com/link/vote?linksId=%s" % nid
yield Request(
url=url,
method="POST",
cookies=self.cookie_dict,
callback=self.show # 对发送点赞请求的返回数据
) # 找到所有的页面
page_urls = Selector(response=response).xpath('//div[@id="dig_lcpage"]//a/@href').extract()
for page in page_urls:
url = "http://dig.chouti.com%s" % page
yield Request(url=url,callback=self.good) # 回调自己，为所有的页面内容点赞 def show(self,response):
# 查看是否点赞成功
print(response.text)
chouti.py
配置文件设置访问深度，可以指定到页面的深度点赞
3.4）cookies小结
Cookie问题
from scrapy.http.cookies import CookieJar
cookie_obj = CookieJar()
cookie_obj.extract_cookies(response,response.request)
print(cookie_obj._cookies)
cookies使用小结
4）scrapy框架扩展
from scrapy.extensions.telnet import TelnetConsole 查看模拟扩展的源代码
自定义扩展内容
from scrapy import signals
class MyExtend: def __init__(self,crawler):
self.crawler = crawler
# 钩子上挂障碍物
# 在指定信号上注册操作
crawler.signals.connect(self.start, signals.engine_started)
crawler.signals.connect(self.close, signals.spider_closed) @classmethod
def from_crawler(cls, crawler):
return cls(crawler) def start(self):
print('signals.engine_started.start') def close(self):
print('signals.spider_closed.close')
extensions.py
配置文件引入extension.py
EXTENSIONS = {
# 'scrapy.extensions.telnet.TelnetConsole': None,
'day96.extensions.MyExtend': ,
}
settings.py
5）配置文件详解
# -*- coding: utf- -*- # Scrapy settings for step8_king project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
# http://doc.scrapy.org/en/latest/topics/settings.html
# http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html
# http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html # . 爬虫名称
BOT_NAME = 'step8_king' # . 爬虫应用路径
SPIDER_MODULES = ['step8_king.spiders']
NEWSPIDER_MODULE = 'step8_king.spiders' # Crawl responsibly by identifying yourself (and your website) on the user-agent
# . 客户端 user-agent请求头
# USER_AGENT = 'step8_king (+http://www.yourdomain.com)' # Obey robots.txt rules
# . 禁止爬虫配置
# ROBOTSTXT_OBEY = False # Configure maximum concurrent requests performed by Scrapy (default: )
# . 并发请求数
# CONCURRENT_REQUESTS = # Configure a delay for requests for the same website (default: )
# See http://scrapy.readthedocs.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
# . 延迟下载秒数
# DOWNLOAD_DELAY = # The download delay setting will honor only one of:
# . 单域名访问并发数，并且延迟下次秒数也应用在每个域名
# CONCURRENT_REQUESTS_PER_DOMAIN =
# 单IP访问并发数，如果有值则忽略：CONCURRENT_REQUESTS_PER_DOMAIN，并且延迟下次秒数也应用在每个IP
# CONCURRENT_REQUESTS_PER_IP = # Disable cookies (enabled by default)
# . 是否支持cookie，cookiejar进行操作cookie
# COOKIES_ENABLED = True
# COOKIES_DEBUG = True # Disable Telnet Console (enabled by default)
# . Telnet用于查看当前爬虫的信息，操作爬虫等...
# 使用telnet ip port ，然后通过命令操作
# TELNETCONSOLE_ENABLED = True
# TELNETCONSOLE_HOST = '127.0.0.1'
# TELNETCONSOLE_PORT = [,] # . 默认请求头
# 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',
# } # Configure item pipelines
# See http://scrapy.readthedocs.org/en/latest/topics/item-pipeline.html
# . 定义pipeline处理请求
# ITEM_PIPELINES = {
# 'step8_king.pipelines.JsonPipeline': ,
# 'step8_king.pipelines.FilePipeline': ,
# } # . 自定义扩展，基于信号进行调用
# Enable or disable extensions
# See http://scrapy.readthedocs.org/en/latest/topics/extensions.html
# EXTENSIONS = {
# # 'step8_king.extensions.MyExtension': ,
# } # . 爬虫允许的最大深度，可以通过meta查看当前深度；0表示无深度
# DEPTH_LIMIT = # . 爬取时，0表示深度优先Lifo(默认)；1表示广度优先FiFo # 后进先出，深度优先
# DEPTH_PRIORITY =
# SCHEDULER_DISK_QUEUE = 'scrapy.squeue.PickleLifoDiskQueue'
# SCHEDULER_MEMORY_QUEUE = 'scrapy.squeue.LifoMemoryQueue'
# 先进先出，广度优先 # DEPTH_PRIORITY =
# SCHEDULER_DISK_QUEUE = 'scrapy.squeue.PickleFifoDiskQueue'
# SCHEDULER_MEMORY_QUEUE = 'scrapy.squeue.FifoMemoryQueue' # . 调度器队列
# SCHEDULER = 'scrapy.core.scheduler.Scheduler'
# from scrapy.core.scheduler import Scheduler # . 访问URL去重
# DUPEFILTER_CLASS = 'step8_king.duplication.RepeatUrl' # Enable and configure the AutoThrottle extension (disabled by default)
# See http://doc.scrapy.org/en/latest/topics/autothrottle.html """
. 自动限速算法
from scrapy.contrib.throttle import AutoThrottle
自动限速设置
. 获取最小延迟 DOWNLOAD_DELAY
. 获取最大延迟 AUTOTHROTTLE_MAX_DELAY
. 设置初始下载延迟 AUTOTHROTTLE_START_DELAY
. 当请求下载完成后，获取其"连接"时间 latency，即：请求连接到接受到响应头之间的时间
. 用于计算的... AUTOTHROTTLE_TARGET_CONCURRENCY
target_delay = latency / self.target_concurrency
new_delay = (slot.delay + target_delay) / 2.0 # 表示上一次的延迟时间
new_delay = max(target_delay, new_delay)
new_delay = min(max(self.mindelay, new_delay), self.maxdelay)
slot.delay = new_delay
""" # 开始自动限速
# AUTOTHROTTLE_ENABLED = True
# The initial download delay
# 初始下载延迟
# AUTOTHROTTLE_START_DELAY =
# The maximum download delay to be set in case of high latencies
# 最大下载延迟
# AUTOTHROTTLE_MAX_DELAY =
# The average number of requests Scrapy should be sending in parallel to each remote server
# 平均每秒并发数
# AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0 # Enable showing throttling stats for every response received:
# 是否显示
# AUTOTHROTTLE_DEBUG = True # Enable and configure HTTP caching (disabled by default)
# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings """
. 启用缓存
目的用于将已经发送的请求或相应缓存下来，以便以后使用 from scrapy.downloadermiddlewares.httpcache import HttpCacheMiddleware
from scrapy.extensions.httpcache import DummyPolicy
from scrapy.extensions.httpcache import FilesystemCacheStorage
"""
# 是否启用缓存策略
# HTTPCACHE_ENABLED = True # 缓存策略：所有请求均缓存，下次在请求直接访问原来的缓存即可
# HTTPCACHE_POLICY = "scrapy.extensions.httpcache.DummyPolicy"
# 缓存策略：根据Http响应头：Cache-Control、Last-Modified 等进行缓存的策略
# HTTPCACHE_POLICY = "scrapy.extensions.httpcache.RFC2616Policy" # 缓存超时时间
# HTTPCACHE_EXPIRATION_SECS = # 缓存保存路径
# HTTPCACHE_DIR = 'httpcache' # 缓存忽略的Http状态码
# HTTPCACHE_IGNORE_HTTP_CODES = [] # 缓存存储的插件
# HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage' """
. 代理，需要在环境变量中设置
from scrapy.contrib.downloadermiddleware.httpproxy import HttpProxyMiddleware 方式一：使用默认
os.environ
{
http_proxy:http://root:woshiniba@192.168.11.11:9999/
https_proxy:http://192.168.11.11:9999/
}
方式二：使用自定义下载中间件 def to_bytes(text, encoding=None, errors='strict'):
if isinstance(text, bytes):
return text
if not isinstance(text, six.string_types):
raise TypeError('to_bytes must receive a unicode, str or bytes '
'object, got %s' % type(text).__name__)
if encoding is None:
encoding = 'utf-8'
return text.encode(encoding, errors) class ProxyMiddleware(object):
def process_request(self, request, spider):
PROXIES = [
{'ip_port': '111.11.228.75:80', 'user_pass': ''},
{'ip_port': '120.198.243.22:80', 'user_pass': ''},
{'ip_port': '111.8.60.9:8123', 'user_pass': ''},
{'ip_port': '101.71.27.120:80', 'user_pass': ''},
{'ip_port': '122.96.59.104:80', 'user_pass': ''},
{'ip_port': '122.224.249.122:8088', 'user_pass': ''},
]
proxy = random.choice(PROXIES)
if proxy['user_pass'] is not None:
request.meta['proxy'] = to_bytes（"http://%s" % proxy['ip_port']）
encoded_user_pass = base64.encodestring(to_bytes(proxy['user_pass']))
request.headers['Proxy-Authorization'] = to_bytes('Basic ' + encoded_user_pass)
print "**************ProxyMiddleware have pass************" + proxy['ip_port']
else:
print "**************ProxyMiddleware no pass************" + proxy['ip_port']
request.meta['proxy'] = to_bytes("http://%s" % proxy['ip_port']) DOWNLOADER_MIDDLEWARES = {
'step8_king.middlewares.ProxyMiddleware': ,
} """ """
. Https访问
Https访问时有两种情况：
. 要爬取网站使用的可信任证书(默认支持)
DOWNLOADER_HTTPCLIENTFACTORY = "scrapy.core.downloader.webclient.ScrapyHTTPClientFactory"
DOWNLOADER_CLIENTCONTEXTFACTORY = "scrapy.core.downloader.contextfactory.ScrapyClientContextFactory" . 要爬取网站使用的自定义证书
DOWNLOADER_HTTPCLIENTFACTORY = "scrapy.core.downloader.webclient.ScrapyHTTPClientFactory"
DOWNLOADER_CLIENTCONTEXTFACTORY = "step8_king.https.MySSLFactory" # https.py
from scrapy.core.downloader.contextfactory import ScrapyClientContextFactory
from twisted.internet.ssl import (optionsForClientTLS, CertificateOptions, PrivateCertificate) class MySSLFactory(ScrapyClientContextFactory):
def getCertificateOptions(self):
from OpenSSL import crypto
v1 = crypto.load_privatekey(crypto.FILETYPE_PEM, open('/Users/wupeiqi/client.key.unsecure', mode='r').read())
v2 = crypto.load_certificate(crypto.FILETYPE_PEM, open('/Users/wupeiqi/client.pem', mode='r').read())
return CertificateOptions(
privateKey=v1, # pKey对象
certificate=v2, # X509对象
verify=False,
method=getattr(self, 'method', getattr(self, '_ssl_method', None))
)
其他：
相关类
scrapy.core.downloader.handlers.http.HttpDownloadHandler
scrapy.core.downloader.webclient.ScrapyHTTPClientFactory
scrapy.core.downloader.contextfactory.ScrapyClientContextFactory
相关配置
DOWNLOADER_HTTPCLIENTFACTORY
DOWNLOADER_CLIENTCONTEXTFACTORY """ """
. 爬虫中间件
class SpiderMiddleware(object): def process_spider_input(self,response, spider):
'''
下载完成，执行，然后交给parse处理
:param response:
:param spider:
:return:
'''
pass def process_spider_output(self,response, result, spider):
'''
spider处理完成，返回时调用
:param response:
:param result:
:param spider:
:return: 必须返回包含 Request 或 Item 对象的可迭代对象(iterable)
'''
return result def process_spider_exception(self,response, exception, spider):
'''
异常调用
:param response:
:param exception:
:param spider:
:return: None,继续交给后续中间件处理异常；含 Response 或 Item 的可迭代对象(iterable)，交给调度器或pipeline
'''
return None def process_start_requests(self,start_requests, spider):
'''
爬虫启动时调用
:param start_requests:
:param spider:
:return: 包含 Request 对象的可迭代对象
'''
return start_requests 内置爬虫中间件：
'scrapy.contrib.spidermiddleware.httperror.HttpErrorMiddleware': ,
'scrapy.contrib.spidermiddleware.offsite.OffsiteMiddleware': ,
'scrapy.contrib.spidermiddleware.referer.RefererMiddleware': ,
'scrapy.contrib.spidermiddleware.urllength.UrlLengthMiddleware': ,
'scrapy.contrib.spidermiddleware.depth.DepthMiddleware': , """
# from scrapy.contrib.spidermiddleware.referer import RefererMiddleware
# Enable or disable spider middlewares
# See http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html
SPIDER_MIDDLEWARES = {
# 'step8_king.middlewares.SpiderMiddleware': ,
} """
. 下载中间件
class DownMiddleware1(object):
def process_request(self, request, spider):
'''
请求需要被下载时，经过所有下载器中间件的process_request调用
:param request:
:param spider:
:return:
None,继续后续中间件去下载；
Response对象，停止process_request的执行，开始执行process_response
Request对象，停止中间件的执行，将Request重新调度器
raise IgnoreRequest异常，停止process_request的执行，开始执行process_exception
'''
pass def process_response(self, request, response, spider):
'''
spider处理完成，返回时调用
:param response:
:param result:
:param spider:
:return:
Response 对象：转交给其他中间件process_response
Request 对象：停止中间件，request会被重新调度下载
raise IgnoreRequest 异常：调用Request.errback
'''
print('response1')
return response def process_exception(self, request, exception, spider):
'''
当下载处理器(download handler)或 process_request() (下载中间件)抛出异常
:param response:
:param exception:
:param spider:
:return:
None：继续交给后续中间件处理异常；
Response对象：停止后续process_exception方法
Request对象：停止中间件，request将会被重新调用下载
'''
return None 默认下载中间件
{
'scrapy.contrib.downloadermiddleware.robotstxt.RobotsTxtMiddleware': ,
'scrapy.contrib.downloadermiddleware.httpauth.HttpAuthMiddleware': ,
'scrapy.contrib.downloadermiddleware.downloadtimeout.DownloadTimeoutMiddleware': ,
'scrapy.contrib.downloadermiddleware.useragent.UserAgentMiddleware': ,
'scrapy.contrib.downloadermiddleware.retry.RetryMiddleware': ,
'scrapy.contrib.downloadermiddleware.defaultheaders.DefaultHeadersMiddleware': ,
'scrapy.contrib.downloadermiddleware.redirect.MetaRefreshMiddleware': ,
'scrapy.contrib.downloadermiddleware.httpcompression.HttpCompressionMiddleware': ,
'scrapy.contrib.downloadermiddleware.redirect.RedirectMiddleware': ,
'scrapy.contrib.downloadermiddleware.cookies.CookiesMiddleware': ,
'scrapy.contrib.downloadermiddleware.httpproxy.HttpProxyMiddleware': ,
'scrapy.contrib.downloadermiddleware.chunked.ChunkedTransferMiddleware': ,
'scrapy.contrib.downloadermiddleware.stats.DownloaderStats': ,
'scrapy.contrib.downloadermiddleware.httpcache.HttpCacheMiddleware': ,
} """
# from scrapy.contrib.downloadermiddleware.httpauth import HttpAuthMiddleware
# Enable or disable downloader middlewares
# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html
# DOWNLOADER_MIDDLEWARES = {
# 'step8_king.middlewares.DownMiddleware1': ,
# 'step8_king.middlewares.DownMiddleware2': ,
# } settings
settings详解
5.1）对于缓存策略选择
# 缓存策略：所有请求均缓存，下次在请求直接访问原来的缓存即可
# HTTPCACHE_POLICY = "scrapy.extensions.httpcache.DummyPolicy" # 简单粗暴，不建议
# 缓存策略：根据Http响应头：Cache-Control、Last-Modified 等进行缓存的策略
# HTTPCACHE_POLICY = "scrapy.extensions.httpcache.RFC2616Policy" # 可以使用 # 缓存超时时间
# HTTPCACHE_EXPIRATION_SECS = # 缓存保存路径
# HTTPCACHE_DIR = 'httpcache' # 缓存忽略的Http状态码
# HTTPCACHE_IGNORE_HTTP_CODES = [] # 缓存存储的插件
# HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage' # 可以使用
缓存策略
6）下载中间键配置
下载中间键编写
# -*- coding: utf- -*- # Define here the models for your spider middleware
#
# See documentation in:
# http://doc.scrapy.org/en/latest/topics/spider-middleware.html from scrapy import signals
from scrapy.core.engine import ExecutionEngine class DownMiddleware1(object):
def process_request(self, request, spider):
'''
请求需要被下载时，经过所有下载器中间件的process_request调用
:param request:
:param spider:
:return:
None,继续后续中间件去下载；
Response对象，停止process_request的执行，开始执行process_response
Request对象，停止中间件的执行，将Request重新调度器
raise IgnoreRequest异常，停止process_request的执行，开始执行process_exception
'''
print('DownMiddleware1.process_request',request.url) def process_response(self, request, response, spider):
'''
spider处理完成，返回时调用
:param response:
:param result:
:param spider:
:return:
Response 对象：转交给其他中间件process_response
Request 对象：停止中间件，request会被重新调度下载
raise IgnoreRequest 异常：调用Request.errback
'''
print('DownMiddleware1.process_response')
return response def process_exception(self, request, exception, spider):
'''
当下载处理器(download handler)或 process_request() (下载中间件)抛出异常
:param response:
:param exception:
:param spider:
:return:
None：继续交给后续中间件处理异常；
Response对象：停止后续process_exception方法
Request对象：停止中间件，request将会被重新调用下载
'''
return None class DownMiddleware2(object):
def process_request(self, request, spider):
'''
请求需要被下载时，经过所有下载器中间件的process_request调用
:param request:
:param spider:
:return:
None,继续后续中间件去下载；
Response对象，停止process_request的执行，开始执行process_response
Request对象，停止中间件的执行，将Request重新调度器
raise IgnoreRequest异常，停止process_request的执行，开始执行process_exception
'''
print('DownMiddleware2.process_request',request.url) def process_response(self, request, response, spider):
'''
spider处理完成，返回时调用
:param response:
:param result:
:param spider:
:return:
Response 对象：转交给其他中间件process_response
Request 对象：停止中间件，request会被重新调度下载
raise IgnoreRequest 异常：调用Request.errback
'''
print('DownMiddleware2.process_response')
return response
middlewares.py
配置文件配置
# Enable or disable downloader middlewares
# See http://scrapy.readthedocs.org/en/latest/topics/downloader-middleware.html
DOWNLOADER_MIDDLEWARES = {
'day96.middlewares.DownMiddleware1': ,
'day96.middlewares.DownMiddleware2': ,
}
settings.py
下载中间件运行流程归纳
DownMiddleware1.process_request http://dig.chouti.com/
DownMiddleware2.process_request http://dig.chouti.com/ DownMiddleware2.process_response
DownMiddleware1.process_response spider.reponse < http://dig.chouti.com/> . process_request下载完成，后续无需下载
. process_response比如有return response
运行流程规律
7）spider 爬虫中间件配置
爬虫中间件编写
class SpiderMiddleware(object):
def process_spider_input(self, response, spider):
'''
下载完成，执行，然后交给parse处理
:param response:
:param spider:
:return:
'''
pass def process_spider_output(self, response, result, spider):
'''
spider处理完成，返回时调用
:param response:
:param result:
:param spider:
:return: 必须返回包含 Request 或 Item 对象的可迭代对象(iterable)
'''
return result def process_spider_exception(self, response, exception, spider):
'''
异常调用
:param response:
:param exception:
:param spider:
:return: None,继续交给后续中间件处理异常；含 Response 或 Item 的可迭代对象(iterable)，交给调度器或pipeline
'''
return None def process_start_requests(self, start_requests, spider):
'''
爬虫启动时调用
:param start_requests:
:param spider:
:return: 包含 Request 对象的可迭代对象
'''
return start_requests
middlewares.py
配置文件配置
# Enable or disable spider middlewares
# See http://scrapy.readthedocs.org/en/latest/topics/spider-middleware.html
SPIDER_MIDDLEWARES = {
'day96.middlewares.SpiderMiddleware': ,
}
settings.py
spcrapy框架链接：https://www.cnblogs.com/linhaifeng/articles/7811861.html