Getting scrapy project settings when script is out

2019-04-22 18:57发布

I have made a Scrapy spider that can be successfully run from a script located in the root directory of the project. As I need to run multiple spiders from different projects from the same script (this will be a django app calling the script upon the user's request), I moved the script from the root of one of the projects to the parent directory. For some reason, the script is no longer able to get the project's custom settings in order to pipeline the scraped results into the database tables. Here is the code from the scrapy docs I'm using to run the spider from a script:

def spiderCrawl():
   settings = get_project_settings()
   settings.set('USER_AGENT','Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)')
   process = CrawlerProcess(settings)
   process.crawl(MySpider3)
   process.start()

Is there some extra module that needs to be imported in order to get the project settings from outside of the project? Or does there need to be some additions made to this code? Below I also have the code for the script running the spiders, thanks.

from ticket_city_scraper.ticket_city_scraper import *
from ticket_city_scraper.ticket_city_scraper.spiders import tc_spider
from vividseats_scraper.vividseats_scraper import *
from vividseats_scraper.vividseats_scraper.spiders import vs_spider 

tc_spider.spiderCrawl()
vs_spider.spiderCrawl()

4条回答
混吃等死
2楼-- · 2019-04-22 19:18

It should work , can you share your scrapy log file

Edit: your approach will not work because ...when you execute the script..it will look for your default settings in

  1. if you have set the environment variable ENVVAR
  2. if you have scrapy.cfg file in you present directory from where you are executing your script and if that file points to valid settings.py directory ,it will load those settings...
  3. else it will run with vanilla settings provided by scrapy ( your case)

Solution 1 create a cfg file inside the directory (outside folder) and give it a path to the valid settings.py file

Solution 2 make your parent directory package , so that absolute path will not be required and you can use relative path

i.e python -m cron.project1

Solution 3

Also you can try something like

Let it be where it is , inside the project directory..where it is working...

Create a sh file...

  • Line 1: Cd to first projects location ( root directory)
  • Line 2 : Python script1.py
  • Line 3. Cd to second projects location
  • Line 4: python script2.py

Now you can execute spiders via this sh file when requested by django

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走好不送
3楼-- · 2019-04-22 19:25

Thanks to some of the answers already provided here, I realised scrapy wasn't actually importing the settings.py file. This is how I fixed it.

TLDR: Make sure you set the 'SCRAPY_SETTINGS_MODULE' variable to your actual settings.py file. I'm doing this in the __init__() func of Scraper.

Consider a project with the following structure.

my_project/
    main.py                 # Where we are running scrapy from
    scraper/
        run_scraper.py               #Call from main goes here
        scrapy.cfg                   # deploy configuration file
        scraper/                     # project's Python module, you'll import your code from here
            __init__.py
            items.py                 # project items definition file
            pipelines.py             # project pipelines file
            settings.py              # project settings file
            spiders/                 # a directory where you'll later put your spiders
                __init__.py
                quotes_spider.py     # Contains the QuotesSpider class

Basically, the command scrapy startproject scraper was executed in the my_project folder, I've added a run_scraper.py file to the outer scraper folder, a main.py file to my root folder, and quotes_spider.py to the spiders folder.

My main file:

from scraper.run_scraper import Scraper
scraper = Scraper()
scraper.run_spiders()

My run_scraper.py file:

from scraper.scraper.spiders.quotes_spider import QuotesSpider
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
import os


class Scraper:
    def __init__(self):
        settings_file_path = 'scraper.scraper.settings' # The path seen from root, ie. from main.py
        os.environ.setdefault('SCRAPY_SETTINGS_MODULE', settings_file_path)
        self.process = CrawlerProcess(get_project_settings())
        self.spider = QuotesSpider # The spider you want to crawl

    def run_spiders(self):
        self.process.crawl(self.spider)
        self.process.start()  # the script will block here until the crawling is finished

Also, note that the settings might require a look-over, since the path needs to be according to the root folder (my_project, not scraper). So in my case:

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

And repeat for all the settings variables you have!

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萌系小妹纸
4楼-- · 2019-04-22 19:32

this could happen because you are no longer "inside" a scrapy project, so it doesn't know how to get the settings with get_project_settings().

You can also specify the settings as a dictionary as the example here:

http://doc.scrapy.org/en/latest/topics/practices.html#run-scrapy-from-a-script

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我欲成王,谁敢阻挡
5楼-- · 2019-04-22 19:34

I have used this code to solve the problem:

from scrapy.settings import Settings

settings = Settings()

settings_module_path = os.environ.get('SCRAPY_ENV', 'project.settings.dev')   
settings.setmodule(settings_module_path, priority='project')

print(settings.get('BASE_URL'))
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