scrapy-rotating-proxies 0.3.2

Rotating proxies for Scrapy

scrapy-rotating-proxies

This package provides a Scrapy middleware to use rotating proxies, check that they are alive and adjust crawling speed.

License is MIT.

Installation

pip install scrapy-rotating-proxies

Usage

Add ROTATING_PROXY_LIST option with a list of proxies to settings.py:

ROTATING_PROXY_LIST = [
    'proxy1.com:8000',
    'proxy2.com:8031',
    # ...
]

You can load it from file if needed:

def load_lines(path):
    with open(path, 'rb') as f:
        return [line.strip() for line in
                f.read().decode('utf8').splitlines()
                if line.strip()]

ROTATING_PROXY_LIST = load_lines('/my/path/proxies.txt')

Then add rotating_proxies middlewares to your DOWNLOADER_MIDDLEWARES:

DOWNLOADER_MIDDLEWARES = {
    # ...
    'rotating_proxies.middlewares.RotatingProxyMiddleware': 610,
    'rotating_proxies.middlewares.BanDetectionMiddleware': 620,
    # ...
}

After this all requests will be proxied using one of the proxies from the ROTATING_PROXY_LIST.

Requests with “proxy” set in their meta are not handled by scrapy-rotating-proxies. To disable proxying for a request set request.meta['proxy'] = None; to set proxy explicitly use request.meta['proxy'] = "<my-proxy-address>".

Concurrency

By default, all default Scrapy concurrency options (DOWNLOAD_DELAY, AUTHTHROTTLE_..., CONCURRENT_REQUESTS_PER_DOMAIN, etc) become per-proxy for proxied requests when RotatingProxyMiddleware is enabled. For example, if you set CONCURRENT_REQUESTS_PER_DOMAIN=2 then spider will be making at most 2 concurrent connections to each proxy, regardless of request url domain.

Customization

scrapy-rotating-proxies keeps track of working and non-working proxies, and re-checks non-working from time to time.

Detection of a non-working proxy is site-specific. By default, scrapy-rotating-proxies uses a simple heuristic: if a response status code is not 200, response body is empty or if there was an exception then proxy is considered dead.

You can override ban detection method by passing a path to a custom BanDectionPolicy in ROTATING_PROXY_BAN_POLICY option, e.g.:

# settings.py
ROTATING_PROXY_BAN_POLICY = 'myproject.policy.MyBanPolicy'

The policy must be a class with response_is_ban and exception_is_ban methods. These methods can return True (ban detected), False (not a ban) or None (unknown). It can be convenient to subclass and modify default BanDetectionPolicy:

# myproject/policy.py
from rotating_proxies.policy import BanDetectionPolicy

class MyPolicy(BanDetectionPolicy):
    def response_is_ban(self, request, response):
        # use default rules, but also consider HTTP 200 responses
        # a ban if there is 'captcha' word in response body.
        ban = super(MyPolicy, self).response_is_ban(request, response)
        ban = ban or b'captcha' in response.body
        return ban

    def exception_is_ban(self, request, exception):
        # override method completely: don't take exceptions in account
        return None

Instead of creating a policy you can also implement response_is_ban and exception_is_ban methods as spider methods, for example:

class MySpider(scrapy.Spider):
    # ...

    def response_is_ban(self, request, response):
        return b'banned' in response.body

    def exception_is_ban(self, request, exception):
        return None

It is important to have these rules correct because action for a failed request and a bad proxy should be different: if it is a proxy to blame it makes sense to retry the request with a different proxy.

Non-working proxies could become alive again after some time. scrapy-rotating-proxies uses a randomized exponential backoff for these checks - first check happens soon, if it still fails then next check is delayed further, etc. Use ROTATING_PROXY_BACKOFF_BASE to adjust the initial delay (by default it is random, from0 to 5 minutes).

Settings

• ROTATING_PROXY_LIST - a list of proxies to choose from;

• ROTATING_PROXY_LOGSTATS_INTERVAL - stats logging interval in seconds, 30 by default;

• ROTATING_PROXY_CLOSE_SPIDER - When True, spider is stopped if there are no alive proxies. If False (default), then when there is no alive proxies all dead proxies are re-checked.

• ROTATING_PROXY_PAGE_RETRY_TIMES - a number of times to retry downloading a page using a different proxy. After this amount of retries failure is considered a page failure, not a proxy failure. Think of it this way: every improperly detected ban cost you ROTATING_PROXY_PAGE_RETRY_TIMES alive proxies. Default: 5.

  It is possible to change this option per-request using max_proxies_to_try request.meta key - for example, you can use a higher value for certain pages if you’re sure they should work.

• ROTATING_PROXY_BACKOFF_BASE - base backoff time, in seconds. Default is 300 (i.e. 5 min).

• ROTATING_PROXY_BAN_POLICY - path to a ban detection policy. Default is 'rotating_proxies.policy.BanDetectionPolicy'.

FAQ

Q: Where to get proxy lists? How to write and maintain ban rules?

A: It is up to you to find proxies and maintain proper ban rules for web sites; scrapy-rotating-proxies doesn’t have anything built-in. There are commercial proxy services like https://crawlera.com/ which can integrate with Scrapy (see https://github.com/scrapy-plugins/scrapy-crawlera) and take care of all these details.

Contributing

• source code: https://github.com/TeamHG-Memex/scrapy-rotating-proxies

• bug tracker: https://github.com/TeamHG-Memex/scrapy-rotating-proxies/issues

To run tests, install tox and run tox from the source checkout.

CHANGES

0.3.2 (2017-06-05)

• fixed proxy authentication issue.

0.3.1 (2017-03-20)

• fixed OverflowError during backoff computation.

0.3 (2017-03-14)

• redirects with empty bodies are no longer considered bans (thanks Diga Widyaprana).

• ROTATING_PROXY_BAN_POLICY option allows to customize ban detection for all spiders.

0.2.3 (2017-03-03)

• max_proxies_to_try request.meta key allows to override ROTATING_PROXY_PAGE_RETRY_TIMES option per-request.

0.2.2 (2017-03-01)

• Update default ban detection rules: scrapy.exceptions.IgnoreRequest is not a ban.

0.2.1 (2017-02-08)

• changed ROTATING_PROXY_PAGE_RETRY_TIMES default value - it is now 5.

0.2 (2017-02-07)

• improved default ban detection rules;

• log ban stats.

0.1 (2017-02-01)

Initial release