從Scrapy項目保存Django模型

Question

我有一個Scrapy項目，我試圖將輸出項保存爲來自Django模型定義（我沒有使用DjangoItem）的對象。

我正在導入Django設置，如指定here。

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) 

setup_django_env(PATH_TO_DJANGO_PROJECT) 

在我的Scrapy項目中，我有一個進程在結束所有項目並將其保存到一個數據庫中的管道類：

from my_django_project.apps.my_books.models import Book, Category, Image 

class DjangoPipeline(object): 

    def process_item(self, item, spider): 
     category = Category.objects.get(name='Horror') 
     book = Book(name='something', category=category) 
     book.save() 
     image = Image(name='something', book=book) 
     image.save() 
     return item 

然而，奇怪的事情發生，在第一個項目，我得到一個錯誤（見下文）。對於其餘的項目一切都很好。假設我有7個項目要保存，所以我在第一個中得到一個錯誤，其他6個保存。

Traceback (most recent call last): 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/scrapy/middleware.py", line 54, in _process_chain 
    return process_chain(self.methods[methodname], obj, *args) 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/scrapy/utils/defer.py", line 65, in process_chain 
    d.callback(input) 
    File "/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/twisted/internet/defer.py", line 243, in callback 
    self._startRunCallbacks(result) 
    File "/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/twisted/internet/defer.py", line 312, in _startRunCallbacks 
    self._runCallbacks() 
--- <exception caught here> --- 
    File "/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/twisted/internet/defer.py", line 328, in _runCallbacks 
    self.result = callback(self.result, *args, **kw) 
    File "https://stackoverflow.com/users/ale/djcode/books/lib/scraper/scraper/djangopipeline.py", line 34, in process_item 
    selected_category = Category.objects.get(name='Horror') 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/manager.py", line 132, in get 
    return self.get_query_set().get(*args, **kwargs) 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/query.py", line 333, in get 
    clone = self.filter(*args, **kwargs) 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/query.py", line 550, in filter 
    return self._filter_or_exclude(False, *args, **kwargs) 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/query.py", line 568, in _filter_or_exclude 
    clone.query.add_q(Q(*args, **kwargs)) 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/sql/query.py", line 1131, in add_q 
    can_reuse=used_aliases) 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/sql/query.py", line 1026, in add_filter 
    negate=negate, process_extras=process_extras) 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/sql/query.py", line 1182, in setup_joins 
    field, model, direct, m2m = opts.get_field_by_name(name) 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/options.py", line 291, in get_field_by_name 
    cache = self.init_name_map() 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/options.py", line 321, in init_name_map 
    for f, model in self.get_all_related_m2m_objects_with_model(): 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/options.py", line 396, in get_all_related_m2m_objects_with_model 
    cache = self._fill_related_many_to_many_cache() 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/options.py", line 410, in _fill_related_many_to_many_cache 
    for klass in get_models(): 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/loading.py", line 167, in get_models 
    self._populate() 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/loading.py", line 61, in _populate 
    self.load_app(app_name, True) 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/db/models/loading.py", line 76, in load_app 
    app_module = import_module(app_name) 
    File "https://stackoverflow.com/users/ale/virtualenvs/books/lib/python2.6/site-packages/django/utils/importlib.py", line 35, in import_module 
    __import__(name) 
exceptions.ImportError: No module named my_books 

如果我做這樣的事情，所有的7個項目得到保存：

from my_django_project.apps.my_app.models import Book, Category, Image 

class DjangoPipeline(object): 

    def process_item(self, item, spider): 
     try: 
      category = Category.objects.get(name='something') 
     except: 
      category = Category.objects.get(name='something') 
     book = Book(name='something', category=category) 
     try: 
      book.save() 
     except: 
      book.save() 
     image = Image(name='something', book=book) 
     try: 
      image.save() 
     except: 
      image.save() 
     return item 

我不知道我做錯了。請有人幫助我嗎？

謝謝！

Answer 1

我有同樣的問題，我找到了解決方案。至少，它對我有用。

在我的情況下，問題出在Django項目的setting.py文件中 - 我沒有將我的應用的FQN (fully qualified name)添加到INSTALLED_APPS元組，但它是簡稱。

說起你的例子，它可能是你添加到INSTALLED_APPSmy_books元素，但不是my_django_project.apps.my_books。

Answer 2

我記得__init__.py文件丟失會導致一些奇怪的問題。你是否擁有所有的模塊？