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Python Scrapy 丝芙兰爬虫

This project is designed to gather information for Skincare Ingredients Look up Website Project. This web crawler download the detail information of all products on www.sephora.com. MongoDB is used to store the data.

Getting Started

Before running,

  • Install dependent packages, enter pip install requirements.txt.

  • Set up database configuration in setting.py(See Settings part).

  • While keeping database active, go to the sephoraCrawler directory and type scrapy crawl sephoracsp. The spider runs automatially.

Implementation

This project is implemented using Scrapy Library with the help of Selenium Web Driver to deal with lazy loading. The works mainly involves:

  • Item fields
  • Scrapy spider
  • Pipelines
  • Download Middleware
  • Settings

Items Fields

items.py defines what attributes an item (a skincare product) has. All the fields are fetched from 'sephora' web page except is_safe and unsafe_ingredients, which are assigned in the pipelines.

Scrapy Spider

The spider extends from CrawlSpider class. It use several rules to filter the link on a web page and parse a product page in a callback function.

rules = (
    Rule(LinkExtractor(allow='shop', restrict_xpaths='//a[@class="css-6w3omd"]')),
    Rule(NextPageLinkExtractor(), follow=True),
    Rule(LinkExtractor(restrict_xpaths='//div[@class="css-115paux"]/a[@class="css-1tguw7u"]'), callback='parse_item_page')
)复制代码
  • The first rule search for all sub_categories links in the page.
  • The second finds the next page button and follow the link.
  • The last one follow the link to the product page and call a function to parse the items.

Pipelines

The purpose of pipelines is to check the ingridents field of each item, whether it contains unsafe ingredients or not. After processing, is_safe and unsafe_ingredients field is assigned to the items.

Middlewares

A download middleware is applied to deal with lazy loading of the products links. Selenium web driver is used to control a headless chrome browser in the middleware.

The loading is triggered only when user scroll the page down to a certain location. There are 5 groups of items that send AJAX seperately in different height, so I scroll 1/5 of the height of the page for 5 times, all the data is loaded.

Settings

In Settings.py, we mainly need to set up:

  • Connection to the database
MONGO_SERVER = "localhost" # Server address
MONGO_PORT = 27017 # Port
MONGO_DB = "sephora" # Database name
MONGO_COLL = "sephora" # Collection name复制代码
  • DOWNLOAD_DELAY & COOKIES_ENABLED(To avoid banned)
DOWNLOAD_DELAY = 5
COOKIES_ENABLED = False复制代码
  • Activate pipelines
ITEM_PIPELINES = {
    'sephoraCrawler.pipelines.SephoracrawlerPipeline': 300,
}复制代码
  • Activate middleware
DOWNLOADER_MIDDLEWARES = {
    'sephoraCrawler.middlewares.DownloadMiddleware': 100,
}复制代码
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