python爬虫系列2-------Scrapy目录结构介绍与配置详解

Scrapy目录结构介绍与配置文件详解

    先上架构图，网上找的，不管懂不懂，先有个印象，结合文件目录和解释去看,结合以后的实践，原理一目了然。

• 创建出scrapy项目目录如下

├── mySpider
│   ├── __init__.py
│   ├── items.py
│   ├── middlewares.py
│   ├── pipelines.py
│   ├── __pycache__
│   ├── settings.py
│   └── spiders
│       ├── __init__.py
│       └── __pycache__
└── scrapy.cfg

• scrapy.cfg文件

# Automatically created by: scrapy startproject
#
# For more information about the [deploy] section see:
# https://scrapyd.readthedocs.io/en/latest/deploy.html

[settings]
default = mySpider.settings

[deploy]
#url = http://localhost:6800/
project = mySpider

    项目基础设置文件，设置爬虫启用的功能，如并发，管道文件等，需要在基础设置文件设置

• init.py 文件为python初始化文件

    为python模块初始化文件，可用__all__函数配置导出参数，也可什么都不写，但是必须要有，否则报错

• items.py 文件

# -*- 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 MyspiderItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    pass

    此文件俗称模型文件，就是存放字段的文件，上面为简单实例，定义字段名称，以自己的任意形式存取数据

• pipelines.py 管道文件

# -*- 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 MyspiderPipeline(object):
    def process_item(self, item, spider):
        return item

    def process_item为固定写法，当数据交给管道文件处理时，在此文件下

• settings.py核心文件，配置如下

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

# Scrapy settings for mySpider 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
#项目名称
BOT_NAME = 'mySpider'
#项目位置
SPIDER_MODULES = ['mySpider.spiders']
#新爬虫启动位置
NEWSPIDER_MODULE = 'mySpider.spiders'


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

# Obey robots.txt rules
#表示爬虫是否遵循robot协议，默认为遵循
ROBOTSTXT_OBEY = True

# Configure maximum concurrent requests performed by Scrapy (default: 16)

#爬虫并发量，默认为16个
#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

#下载延时为3秒，下载太快压力会大，自行设置
#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)

#是否启动cookies,双刃剑，在爬取需要登录的网站时，需要，但是如果不需要登录则不需要，更好的隐藏身份
#COOKIES_ENABLED = False

# Disable Telnet Console (enabled by default)
#TELNETCONSOLE_ENABLED = False

# Override the default request headers:

#请求报头设置，这里设置就不用程序设置了，如：User-Agent设置
#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

# 爬虫中间件
#SPIDER_MIDDLEWARES = {
#    'mySpider.middlewares.MyspiderSpiderMiddleware': 543,
#}

# Enable or disable downloader middlewares
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html

# 下载中间件，数字代表优先级
#DOWNLOADER_MIDDLEWARES = {
#    'mySpider.middlewares.MyspiderDownloaderMiddleware': 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

# ** 比较重要，管道文件，表示下载好的数据如何处理

#ITEM_PIPELINES = {
#    'mySpider.pipelines.MyspiderPipeline': 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'

• spiders文件—爬虫文件

cd spiders
#命令创建一个爬虫文件，最后的是资源uri
scrapy genspider myspider alinetgo.com

创建完毕 模板内容

# -*- coding: utf-8 -*-
import scrapy


class MyspiderSpider(scrapy.Spider):
    name = 'myspider'
    allowed_domains = ['alinetgo.com']
    start_urls = ['http://alinetgo.com/']

    def parse(self, response):
        pass

    有些不懂的不需要着急，以后慢慢详细介绍


未完待续。。。。