如何在Scrapy的pipelines.py文件中导入Django模型

Question

我正在尝试在我的 pipelines.py 文件中导入一个 Django 应用的模型，以便使用 Django 的 ORM 来保存数据。我在第一个涉及的 Django 应用 "app1" 中创建了一个 Scrapy 项目 scrapy_project（顺便问一下，这样做合适吗？）。

我在 Scrapy 的设置文件中添加了以下几行：

def setup_django_env(path):
  import imp, os
  from django.core.management import setup_environ

  f, filename, desc = imp.find_module('settings', [path])
  project = imp.load_module('settings', f, filename, desc)

  setup_environ(project)

current_dir = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
setup_django_env(os.path.join(current_dir, '../../d_project1'))

当我尝试导入我的 Django 应用 app1 的模型时，出现了这个错误信息：

Traceback (most recent call last):
  File "/usr/local/bin/scrapy", line 4, in <module>
    execute()
  File "/usr/local/lib/python2.7/dist-packages/scrapy/cmdline.py", line 122, in execute
    _run_print_help(parser, _run_command, cmd, args, opts)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/cmdline.py", line 76, in     _run_print_help
    func(*a, **kw)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/cmdline.py", line 129, in     _run_command
    cmd.run(args, opts)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/commands/crawl.py", line 43, in     run
    spider = self.crawler.spiders.create(spname, **opts.spargs)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/command.py", line 33, in crawler
    self._crawler.configure()
  File "/usr/local/lib/python2.7/dist-packages/scrapy/crawler.py", line 41, in configure
    self.engine = ExecutionEngine(self, self._spider_closed)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/core/engine.py", line 63, in     __init__
    self.scraper = Scraper(crawler)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/core/scraper.py", line 66, in     __init__
    self.itemproc = itemproc_cls.from_crawler(crawler)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/middleware.py", line 50, in     from_crawler
    return cls.from_settings(crawler.settings, crawler)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/middleware.py", line 29, in     from_settings
    mwcls = load_object(clspath)
  File "/usr/local/lib/python2.7/dist-packages/scrapy/utils/misc.py", line 39, in     load_object
    raise ImportError, "Error loading object '%s': %s" % (path, e)
ImportError: Error loading object 'scrapy_project.pipelines.storage.storage': No module         named dydict.models

为什么 Scrapy 不能访问 Django 应用的模型（考虑到 app1 已经在 installed_app 中）？

Answer 1

在数据处理的流程中，你不需要直接导入Django的模型，而是要使用与Django模型关联的Scrapy模型。

你需要在Scrapy的设置中添加Django的配置，而不是在之后再添加。

如果想在Scrapy项目中使用Django模型，你需要使用django_Item，具体可以参考这个链接：https://github.com/scrapy-plugins/scrapy-djangoitem（要把它导入到你的Python路径中）。

我推荐的文件结构是：

Projects
 |-DjangoScrapy
     |-DjangoProject
     |     |-Djangoproject
     |     |-DjangoAPP
     |-ScrapyProject
            |-ScrapyProject
                 |-Spiders

然后在你的Scrapy项目中，你需要添加Django项目的完整路径到Python路径：

**# Setting up django's project full path.**
import sys
sys.path.insert(0, '/home/PycharmProject/scrap/DjangoProject')

# Setting up django's settings module name.
import os
os.environ['DJANGO_SETTINGS_MODULE'] = 'DjangoProject.settings'

接着在你的items.py文件中，你可以把Django模型和Scrapy模型关联起来：

from DjangoProject.models import Person, Job
from scrapy_djangoitem import DjangoItem

class Person(DjangoItem):
    django_model = Person
class Job(DjangoItem):
    django_model = Job

之后你可以在数据处理的流程中使用.save()方法来保存对象：

spider.py

from scrapy.spider import BaseSpider
from mybot.items import PersonItem

class ExampleSpider(BaseSpider):
    name = "example"
    allowed_domains = ["dmoz.org"]
    start_urls = ['http://www.dmoz.org/World/Espa%C3%B1ol/Artes/Artesan%C3%ADa/']

    def parse(self, response):
        # do stuff
        return PersonItem(name='zartch')

pipelines.py

from myapp.models import Person

class MybotPipeline(object):
    def process_item(self, item, spider):
        obj = Person.objects.get_or_create(name=item['name'])
        return obj

我有一个最简代码的仓库可以参考：（你只需要在Scrapy设置中设置你的Django项目路径）https://github.com/Zartch/Scrapy-Django-Minimal

在这里：https://github.com/Zartch/Scrapy-Django-Minimal/blob/master/mybot/mybot/settings.py，你需要把我的Django项目路径改成你自己Django项目的路径：

sys.path.insert(0, '/home/zartch/PycharmProjects/Scrapy-Django-Minimal/myweb')

Answer 2

试试：

from .. models import MyModel 

或者

from ... models import MyModel

每个点代表一个位置