scrapy基本用法详解（入门）

歪小Y_02 发表于 2019-2-25 17:22:23

我们要抓取的网站是：quotes.toscrape.com
流程框架：
1.抓取第一页
2.获取内容和下一页的链接
3保存爬取结果、
4翻页爬取，请求下一页信息，分析内容并请求再下一页的链接

在命令行下如下操作：
创建项目：scrapy startproject quote
创建spider文件：scrapy genspider quotes quotes.toscrtapy.com
然后用pycharm打开

quotes.py
# -*- coding: utf-8 -*-
import scrapy
from quote.items import QuoteItem

class QuotesSpider(scrapy.Spider):
name = 'quotes'
# name指定spidedr的名称
allowed_domains = ['quotes.toscrape.com']
start_urls = ['http://quotes.toscrape.com/']

def parse(self, response):
   # parse方法是默认的回调，当爬虫开始时会从start_url得到链接，
   # 然后自动调用parse方法进行解析
   quotes =response.css('.quote')
   # 选择出每一个区域块
   for quote in quotes:# 循环每一个区域块
         item = QuoteItem()
         text = quote.css('.text::text').extract_first()
         author = quote.css('.author::text').extract_first()
         tags = quote.css('.tags .tag::text').extract()
         item['text'] = text
         item['author'] = author
         item['tags'] = tags
         yield item

   # .text::text意思是获取class=text的文本内容
   next = response.css('.pager .next a::attr(href)').extract_first()
   # 得到的只是url的一部分
   url = response.urljoin(next)
   # 使用join构建完整的url
   yield scrapy.Request(url=url,callback=self.parse)
   # 生成request

   # 命令行下数据的保存：scrapy crawl quotes -o quotes.json
   #也支持数据格式：('json', 'jsonlines', 'jl', 'csv', 'xml', 'marshal', 'pickle')

setting.py
# -*- coding: utf-8 -*-

# Scrapy settings for quote 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 = 'quote'

SPIDER_MODULES = ['quote.spiders']
NEWSPIDER_MODULE = 'quote.spiders'

# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'quote (+http://www.yourdomain.com)'

# Obey robots.txt rules
ROBOTSTXT_OBEY = True

# 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 = {
# 'quote.middlewares.QuoteSpiderMiddleware': 543,
#}

# Enable or disable downloader middlewares
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES = {
# 'quote.middlewares.QuoteDownloaderMiddleware': 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 = {
# 'quote.pipelines.QuotePipeline': 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'

items.py
# -*- coding: utf-8 -*-

# Define here the models for your scraped items
#
# See documentation in:
# https://doc.scrapy.org/en/latest/topics/items.html

import scrapy

class QuoteItem(scrapy.Item):
text = scrapy.Field()
author = scrapy.Field()
tags = scrapy.Field()

# define the fields for your item here like:
# name = scrapy.Field()

piplines.py
# -*- 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
## 对item进行处理，保存到数据库当中
from scrapy.exceptions import DropItem
class TextPipeline(object):
def __init__(self):
   self.limit = 50

def process_item(self, item, spider):
   if item['text']:
      if len(item['text']) > self.limit:
            item['text'] = item['text'].rstrip() + '...'

      return item
   else:
         return DropItem('missing Text')

Miss_love 发表于 2019-2-25 22:39:35

学习了

Miss_love 发表于 2021-1-5 13:40:16

支持分享

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scrapy基本用法详解（入门）