Question

我无法在帖子的现有评论列表中添加新评论。这是模型：

KeyError                                  Traceback (most recent call last)
~\anaconda3\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
   2645             try:
-> 2646                 return self._engine.get_loc(key)
   2647             except KeyError:

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

KeyError: 'Date'

During handling of the above exception, another exception occurred:

KeyError                                  Traceback (most recent call last)
<ipython-input-70-86e494615bb1> in <module>
      1 df = pd.DataFrame()
      2 for ticker in tickers:
----> 3     df2 = pdr.DataReader(ticker,'yahoo',start,end)
      4     df[ticker] = df2['Adj Close']

~\anaconda3\lib\site-packages\pandas\util\_decorators.py in wrapper(*args, **kwargs)
    212                 else:
    213                     kwargs[new_arg_name] = new_arg_value
--> 214             return func(*args, **kwargs)
    215 
    216         return cast(F, wrapper)

~\anaconda3\lib\site-packages\pandas_datareader\data.py in DataReader(name, data_source, start, end, retry_count, pause, session, api_key)
    382             retry_count=retry_count,
    383             pause=pause,
--> 384             session=session,
    385         ).read()
    386 

~\anaconda3\lib\site-packages\pandas_datareader\base.py in read(self)
    251         # If a single symbol, (e.g., 'GOOG')
    252         if isinstance(self.symbols, (string_types, int)):
--> 253             df = self._read_one_data(self.url, params=self._get_params(self.symbols))
    254         # Or multiple symbols, (e.g., ['GOOG', 'AAPL', 'MSFT'])
    255         elif isinstance(self.symbols, DataFrame):

~\anaconda3\lib\site-packages\pandas_datareader\yahoo\daily.py in _read_one_data(self, url, params)
    163         prices = DataFrame(data["prices"])
    164         prices.columns = [col.capitalize() for col in prices.columns]
--> 165         prices["Date"] = to_datetime(to_datetime(prices["Date"], unit="s").dt.date)
    166 
    167         if "Data" in prices.columns:

~\anaconda3\lib\site-packages\pandas\core\frame.py in __getitem__(self, key)
   2798             if self.columns.nlevels > 1:
   2799                 return self._getitem_multilevel(key)
-> 2800             indexer = self.columns.get_loc(key)
   2801             if is_integer(indexer):
   2802                 indexer = [indexer]

~\anaconda3\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
   2646                 return self._engine.get_loc(key)
   2647             except KeyError:
-> 2648                 return self._engine.get_loc(self._maybe_cast_indexer(key))
   2649         indexer = self.get_indexer([key], method=method, tolerance=tolerance)
   2650         if indexer.ndim > 1 or indexer.size > 1:

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

KeyError: 'Date'

这是视图：

class Comment(models.Model):
    post = models.ForeignKey(Post, on_delete=models.CASCADE, related_name='comments')
    body = models.TextField()
    commented_by = models.ForeignKey(User, on_delete=models.CASCADE)
    commented_on = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return f'Commented by {self.commented_by} on {self.post}.'

Answer 1

基本上，当您尝试保存新评论时，您将错误的模型实例传递给表单：

form = CommentForm(request.POST, instance=post)
                                 ^^^^^^^^^^^^^

实际上没有必要这样做，您可以简单地通过以下方式声明表单实例：

form = CommentForm(request.POST)

这是一个小的重构代码：

def post_detail(request, id):
    post = Post.objects.get(id=id)
    form = CommentForm(request.POST or None)
    if request.method == 'POST':
        if form.is_valid():
            instance = form.save(commit=False)
            instance.post = post
            # instance.comment_by = request.user
            instance.save()
    comments = post.comments.all().order_by('-commented_on')
    total_comments = comments.count()
    context = {
        'post' : post,
        'comments' : comments,
        'form' : form,
        'total_comments' : total_comments,
    }
    return render(request, 'blog/detail.html', context)

Django 博客评论

1 个答案: