使用Scrapy抓取多个页面和多个URL

6kkfgxo0  于 2022-11-09  发布在  其他
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我以前做过一个小项目,用BeautifulSoup抓取一个真实的地产网站,但是抓取大约5,000个数据点花了很长时间。我想学习多线程处理,然后用BS实现它,但是有人告诉我,用Scrapy抓取网页可能更快更容易。另外,我已经从使用Spyder切换到Pycharm作为我的IDE。它仍然是不和谐的经验,但我正在努力适应它。
我已经看过一次文档,并遵循了一些使用Scrapy抓取的例子,但我仍然遇到困难。我计划使用我以前创建的BS抓取脚本作为基础,并创建一个新的Scrapy项目来网页抓取真实的地产数据。但是,我不知道如何以及从哪里开始。任何和所有的帮助都非常感谢。谢谢。

**想要的结果:**使用Scrapy从多个URL抓取多个页面。输入公寓清单链接并从每个链接取得数据,即可抓取多个值。
Scrapy脚本(目前为止):


# -*- coding: utf-8 -*-

# Import library

import scrapy

# Create Spider class

class UneguiApartmentSpider(scrapy.Spider):
    name = 'apartments'
    allowed_domains = ['www.unegui.mn']
    start_urls = [
        'https://www.unegui.mn/l-hdlh/l-hdlh-zarna/oron-suuts-zarna/'
        ]
    # headers
    headers = {
        "user-agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4577.63 Safari/537.36"
    }

    def parse(self, response):
        for listings in response.xpath("//div[@class='list-announcement']"):
            item = ApartmentsItem()
            item['name'] = listings.xpath('text()').extract()
            item['link'] = listings.xpath('href').extract()
        yield item

靓汤剧本:

这个脚本仍然有一些问题,我试图解决,如刮城市和价格。例如,为4卧室公寓url(/4-r/),它创建一个错误或空值,因为有VIP列表


# -*- coding: utf-8 -*-

import requests
from bs4 import BeautifulSoup as BS
from datetime import datetime, timedelta
from dateutil.relativedelta import relativedelta
from timeit import default_timer as timer
import pandas as pd
import re
import csv

dt_today = datetime.today()
date_today = dt_today.strftime('%Y-%m-%d')
date_today2 = dt_today.strftime('%Y%m%d')
date_yesterday = (dt_today-relativedelta(day=1)).strftime('%Y-%m-%d')

def main():
    page = 0
    name = []
    date = []
    address = []
    district = []
    city = []
    price = []
    area_sqm = []
    rooms = []
    floor = []
    commission_year = []
    building_floors = []
    garage = []
    balcony = []
    windows = []
    window_type = []
    floor_type = []
    door_type = []
    leasing = []
    description = []
    link = []

    for i in range (5,6):
        BASE = 'https://www.unegui.mn'
        URL = f'{BASE}/l-hdlh/l-hdlh-zarna/oron-suuts-zarna/{i}-r/?page='
        COLUMNS=['Name','Date','Address','District','City','Price','Area_sqm','Rooms','Floor','Commission_year',
                 'Building_floors','Garage', 'Balcony','Windows','Window_type','Floor_type','door_type','Leasing','Description','Link']

        with requests.Session() as session:
            while True:
                (r := session.get(f'{URL}{page+1}')).raise_for_status()
                m = re.search('.*page=(\d+)$', r.url)
                if m and int(m.group(1)) == page:
                    break
                page += 1
                start = timer()
                print(f'Scraping {i} bedroom apartments page {page}')

                soup = BS(r.text, 'lxml')
                for tag in soup.findAll('div', class_='list-announcement-block'):
                    _name = tag.find('a', attrs={'itemprop': 'name'})
                    name.append(_name.get('content', 'N/A'))
                    if (_link := _name.get('href', None)):
                        link.append(f'{BASE}{_link}')
                        (_r := session.get(link[-1])).raise_for_status()
                        _spanlist = BS(_r.text, 'lxml').find_all('span', class_='value-chars')
                        floor_type.append(_spanlist[0].get_text().strip())
                        balcony.append(_spanlist[1].get_text().strip())
                        garage.append(_spanlist[2].get_text().strip())
                        window_type.append(_spanlist[3].get_text().strip())
                        door_type.append(_spanlist[4].get_text().strip())   
                        windows.append(_spanlist[5].get_text().strip())

                        _alist = BS(_r.text, 'lxml').find_all('a', class_='value-chars')
                        commission_year.append(_alist[0].get_text().strip())
                        building_floors.append(_alist[1].get_text().strip())
                        area_sqm.append(_alist[2].get_text().strip())
                        floor.append(_alist[3].get_text().strip())
                        leasing.append(_alist[4].get_text().strip())
                        district.append(_alist[5].get_text().strip())
                        address.append(_alist[6].get_text().strip())

                        rooms.append(tag.find('div', attrs={'announcement-block__breadcrumbs'}).get_text().split('»')[1].strip())
                        description.append(tag.find('div', class_='announcement-block__description').get_text().strip())
                        date.append(tag.find('div', class_='announcement-block__date').get_text().split(',')[0].strip())
                        city.append(tag.find('div', class_='announcement-block__date').get_text().split(',')[1].strip())         
                        # if ( _price := tag.find('div', class_='announcement-block__price _premium')) is None:
                        #     _price = tag.find('meta', attrs={'itemprop': 'price'})['content']

                        # price.append(_price)
                        end = timer()
                print(timedelta(seconds=end-start))

            df = pd.DataFrame(zip(name, date, address, district, city, 
                                  price, area_sqm, rooms, floor, commission_year,
                                  building_floors, garage, balcony, windows, window_type,
                                  floor_type, door_type, leasing, description, link), columns=COLUMNS)
            return(df)

        df['Date'] = df['Date'].replace('Өнөөдөр', date_today)
        df['Date'] = df['Date'].replace('Өчигдөр', date_yesterday)
        df['Area_sqm'] = df['Area_sqm'].replace('м²', '')
        df['Balcony'] = df['Balcony'].replace('тагттай', '')

if __name__ == '__main__':
    df = main()
    df.to_csv(f'{date_today2}HPD.csv', index=False)
pgccezyw

pgccezyw1#

这是一个抓取同一网站的多个URL的示例,例如,该网站是amazon,第一个URL用于婴儿类别,第二个URL用于另一个类别

import scrapy

class spiders(scrapy.Spider):
    name = "try"
    start_urls = ["https://www.amazon.sg/gp/bestsellers/baby/ref=zg_bs_nav_0",'https://www.amazon.sg/gp/browse.html?node=6537678051&ref_=nav_em__home_appliances_0_2_4_4']

    def parse(self, response):
        for url in response.css('.mr-directory-item a::attr(href)').getall(): #loop for each href
            yield scrapy.Request(f'https://muckrack.com{url}', callback=self.parse_products,
                                 dont_filter=True)
    def parse_products(self, response):

# these are for another website

        full_name = response.css('.mr-font-family-2.top-none::text').get()
        Media_outlet = response.css('.mr-person-job-item a::text').get()

        yield {'Full Name': full_name, 'Media outlet':Media_outlet,'URL': response.url}

如果要对每个URL执行不同的处理,则应使用

import scrapy

class spiders(scrapy.Spider):
    name = "try"

    def start_requests(self):
        yield scrapy.Request('url1',callback=self.parse1)
        yield scrapy.Request('url2',callback=self.parse2)

    def parse1(self, response):
        for url in response.css('.mr-directory-item a::attr(href)').getall():#loop for each href
            yield scrapy.Request(f'https://muckrack.com{url}', callback=self.parse_products,
                                 dont_filter=True)
    def parse2(self, response):
        for url in response.css('.mr-directory-item a::attr(href)').getall():#loop for each href
            yield scrapy.Request(f'https://muckrack.com{url}', callback=self.parse_products,
                                 dont_filter=True)

    def parse_products(self, response):
        #these are for another website 
        full_name = response.css('.mr-font-family-2.top-none::text').get()
        Media_outlet = response.css('.mr-person-job-item a::text').get()
       #yield {'header':'data'}
        yield {'Full Name': full_name, 'Media outlet':Media_outlet,'URL': response.url}```
ekqde3dh

ekqde3dh2#

Scrapy是一个异步回调驱动的框架。
parse()方法是所有start_urls的默认回调函数。现在,每个回调函数都可以产生以下两种结果之一:

  • 项目-将其发送到管道(如果有)和输出
  • 可以生成request -scrapy.Request对象以继续进行擦除。

因此,如果你有多个页面scraper,你想刮所有的项目,你的逻辑看起来像这样:

class MySpider(Spider):
   name = "pagination_spider"
   start_urls = ["first_page_url"]

   def parse(self, response):
       total_pages = ... # find total pages number in first page
       for page in range(1, total_pages):
           url = base_url + page  # form page url 
           yield scrapy.Request(url, callback=self.parse_page)
       # also don't forget to parse first page
       yield from self.parse_page(self, response)

   def parse_page(self, response):
       """parse listing items from single pagination page"""
       item = {}  # parse page response for listing items
       yield item

在这里,蜘蛛将请求第一个页面,然后调度请求所有其余的页面并发-这意味着你可以充分利用scrapy的速度,以获得所有的清单。

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