[Scrapy] How to use Crawler in Python

About Scrapy

최근 기계학습을 위한 데이터의 수집 및 전처리 과정등을 위해 웹 크롤러의 역할이 점차 중요해지고 있다. Scrapy는 파이썬 웹 크롤러 프레임워크로 데이터의 수집, 가공, 적재과정을 손쉽게 구현 가능한 인터페이스를 제공한다. 
웹 URL을 이용하여 다양한 Format의 (HTML, JSON, XML 등)문서를 수집 및 정제하여 pipeline을 통해 적재(Csv file, Json file, MySQL 등)까지의 프로세스를 구현할 수 있다.

사용기술 목록

• Python 3.6.9 - 파이썬
• Scrapy 1.6.0 - 파이썬 오픈소스 Cralwer

Installation

Python Scrapy 설치

$ pip install scrapy
$ pip install scrapy_user_agents  #random user-agent를 생성하기 위해 사용

Writing a Spider

데이터 수집 및 정제과정을 거쳐 정형화된 모델로 변환 후 파일 및 DB에 적재까지의 과정을 작성한다.

settings.py

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

# Scrapy settings for crawler project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
#     https://docs.scrapy.org/en/latest/topics/settings.html
#     https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#     https://docs.scrapy.org/en/latest/topics/spider-middleware.html

BOT_NAME = 'crawler'

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


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

# Obey robots.txt rules
# ROBOTSTXT_OBEY = True
# 2020.07.03 by rocksea
ROBOTSTXT_OBEY = False

# 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://docs.scrapy.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
#DOWNLOAD_DELAY = 3
# 2020.07.06 by rocksea
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://docs.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
#    'crawler.middlewares.CrawlerSpiderMiddleware': 543,
#}

# Enable or disable downloader middlewares
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES = {
#    'crawler.middlewares.CrawlerDownloaderMiddleware': 543,
#}
# 2020.07.03 by rocksea
DOWNLOADER_MIDDLEWARES = {
    'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware': None,
    'scrapy_user_agents.middlewares.RandomUserAgentMiddleware': 400,
}

# Enable or disable extensions
# See https://docs.scrapy.org/en/latest/topics/extensions.html
#EXTENSIONS = {
#    'scrapy.extensions.telnet.TelnetConsole': None,
#}

# Configure item pipelines
# See https://docs.scrapy.org/en/latest/topics/item-pipeline.html
#ITEM_PIPELINES = {
#    'crawler.pipelines.CrawlerPipeline': 300,
#}
# 2020.07.03 by rocksea
ITEM_PIPELINES = {'crawler.pipelines.CsvPipeline': 300,}

# Enable and configure the AutoThrottle extension (disabled by default)
# See https://docs.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://docs.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://docs.scrapy.org/en/latest/topics/items.html

import scrapy


class NaverKinItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    qTitle = scrapy.Field()
    qContent = scrapy.Field()
    aContent = scrapy.Field()
    aDt= scrapy.Field()
    qDt= scrapy.Field()
    pass

NaverKinSpider.py

# -*- coding: utf-8 -*-
import scrapy
import json
import time
import re
from datetime import datetime, timedelta
from crawler.items import NaverKinItem

class NaverKinSpider(scrapy.Spider):
    name = "NaverKinCrawler"

    def __init__(self, keyword='', **kwargs):
        self.keyword = keyword
        self.download_delay = 5
        super().__init__(**kwargs)

    def start_requests(self):
        now = datetime.now()

        for page in range(10) :
           params = {'kin_start':(page*10)+1}
           url = "https://search.naver.com/search.naver?where=kin&kin_display=10&query={}&sm=tab_pge&kin_start={}".format(self.keyword, params['kin_start'])
           request = scrapy.Request(url, self.parse_data)
           request.meta['params'] = params
           yield request

    def parse_data(self, response):
        item = NaverKinItem()

        #print("#### Resp Body: \n %s" % response.body)
        for resultArea in response.xpath(r'//*[@id="elThumbnailResultArea"]/li'):
            title = resultArea.xpath(r'dl/dt/a')[0].extract()
            title = re.sub(r'<.*?>','',title) #strip html
            print("#### title : %s" % title)

            content = resultArea.xpath(r'dl/dd[2]')[0].extract()
            content = re.sub(r'<.*?>','',content) #strip html
            print("#### content : %s" % content)

            qDt = resultArea.xpath(r'dl/dd[1]/text()')[0].extract()
            qDt = re.sub(r'([0-9]{4}.[0-9]{2}.[0-9]{2}).*',r'\1',qDt).replace('.','-') #Formatting DateType
            print("#### question Date : %s" % qDt)

            aContent = resultArea.xpath(r'dl/dd[3]')[0].extract()
            aContent = re.sub(r'<.*?>','',aContent) #strip html
            print("#### answer : %s" % aContent)

            #Setting item
            item['qTitle'] = title
            item['qContent'] = content
            item['aContent'] = aContent
            item['qDt'] = qDt
            item['aDt'] = ''

            yield item

pipelines.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

from __future__ import unicode_literals
from scrapy.exporters import JsonItemExporter, CsvItemExporter
from scrapy.exceptions import DropItem
import sys

class JsonPipeline(object):
    def __init__(self):
        self.file = open("crawler_data.json", 'wb')
        self.exporter = JsonItemExporter(self.file, encoding='utf-8', ensure_ascii=False)
        self.exporter.start_exporting()

    def close_spider(self, spider):
        self.exporter.finish_exporting()
        self.file.close()

    def process_item(self, item, spider):
        return item

class CsvPipeline(object):
    def __init__(self):
        self.file = open("crawler_data.csv", 'wb')
        self.exporter = CsvItemExporter(self.file, encoding='utf-8')
        self.exporter.start_exporting()

    def close_spider(self, spider):
        self.exporter.finish_exporting()
        self.file.close()

    def process_item(self, item, spider):
        self.exporter.export_item(item)
        return item

Run Crawler

Crawler 실행 명령어:

$ scrapy crawl [크롤러명]

이제 실제 작성한 Spider를 실행해보도록 한다

$ scrapy crawl NaverKinCrawler -a keyword=키워드

GitHub

https://github.com/rocksea/cralwer