Scrapy-link-filter

Spider Middleware that allows a Scrapy Spider to filter requests. There is similar functionality in the CrawlSpider already using Rules and in the RobotsTxtMiddleware, but there are twists. This middleware allows defining rules dinamically per spider, or job, or request.

Install

This project requires Python 3.6+ and pip. Using a virtual environment is strongly encouraged.

$ pip install git+https://github.com/croqaz/scrapy-link-filter

Usage

For the middleware to be enabled as a Spider Middleware, it must be added in the project settings.py:

SPIDER_MIDDLEWARES = {
    # maybe other Spider Middlewares ...
    # can go after DepthMiddleware: 900
    'scrapy_link_filter.middleware.LinkFilterMiddleware': 950,
}

Or, it can be enabled as a Downloader Middleware, in the project settings.py:

DOWNLOADER_MIDDLEWARES = {
    # maybe other Downloader Middlewares ...
    # can go before RobotsTxtMiddleware: 100
    'scrapy_link_filter.middleware.LinkFilterMiddleware': 50,
}

The rules must be defined either in the spider instance, in a spider.extract_rules dict, or per request, in request.meta['extract_rules']. Internally, the extract_rules dict is converted into a LinkExtractor, which is used to match the requests.

Example of a specific allow filter:

extract_rules = {"allow_domains": "example.com", "allow": "/en/items/"}

Or a specific deny filter:

extract_rules = {
    "deny_domains": ["whatever.com", "ignore.me"],
    "deny": ["/privacy-policy/?$", "/about-?(us)?$"]
}

The allowed fields are:

• allow_domains and deny_domains - one, or more domains to specifically limit to, or specifically reject
• allow and deny - one, or more sub-strings, or patterns to specifically allow, or reject

License

BSD3 © Cristi Constantin.