小编Nil*_*Kar的帖子

我在我的项目中做了以下信号：

@receiver(pre_save, sender=group1)
@disable_for_loaddata
def total_closing_group1(sender,instance,*args,**kwargs):
    total_group_closing_deb_po = instance.master_group.filter(ledgergroups__Closing_balance__gte=0,balance_nature='Debit').aggregate(the_sum=Coalesce(Sum('ledgergroups__Closing_balance'), Value(0)))['the_sum']
    total_group_closing_deb_neg = instance.master_group.filter(ledgergroups__Closing_balance__lt=0,balance_nature='Debit').aggregate(the_sum=Coalesce(Sum('ledgergroups__Closing_balance'), Value(0)))['the_sum']
    total_group_closing_po_cre = instance.master_group.filter(ledgergroups__Closing_balance__gte=0,balance_nature='Credit').aggregate(the_sum=Coalesce(Sum('ledgergroups__Closing_balance'), Value(0)))['the_sum']
    total_group_closing_neg_cre = instance.master_group.filter(ledgergroups__Closing_balance__lt=0,balance_nature='Credit').aggregate(the_sum=Coalesce(Sum('ledgergroups__Closing_balance'), Value(0)))['the_sum']
    total_closing_deb_po = instance.ledgergroups.filter(Closing_balance__gte=0,group1_Name__balance_nature='Debit').aggregate(the_sum=Coalesce(Sum('Closing_balance'), Value(0)))['the_sum']
    total_closing_deb_ne = instance.ledgergroups.filter(Closing_balance__lt=0,group1_Name__balance_nature='Debit').aggregate(the_sum=Coalesce(Sum('Closing_balance'), Value(0)))['the_sum']
    total_closing_cre_po = instance.ledgergroups.filter(Closing_balance__gte=0,group1_Name__balance_nature='Credit').aggregate(the_sum=Coalesce(Sum('Closing_balance'), Value(0)))['the_sum']
    total_closing_cre_ne = instance.ledgergroups.filter(Closing_balance__lt=0,group1_Name__balance_nature='Credit').aggregate(the_sum=Coalesce(Sum('Closing_balance'), Value(0)))['the_sum']
    if total_group_closing_deb_po != None and total_group_closing_neg_cre != None and total_closing_deb_po != None and total_closing_cre_ne != None:
        instance.positive_closing = total_group_closing_deb_po + abs(total_group_closing_neg_cre) + total_closing_deb_po + abs(total_closing_cre_ne)
    if total_group_closing_po_cre != None and total_group_closing_deb_neg != None and total_closing_cre_po != None and total_closing_deb_ne != None:    
        instance.negative_closing …

我的模特：

class GroupBase(models.Model):
    """
    Predefined base group name
    """
    YesNo = (
        ('Yes', 'Yes'),
        ('No', 'No')
    )
    name = models.CharField(max_length=32, unique=True)
    parent = models.CharField(max_length=20)
    is_revenue = models.CharField(max_length=3, choices=YesNo, default='No')
    affects_trading = models.CharField(max_length=3, choices=YesNo, default='No')
    is_debit = models.CharField(max_length=3, choices=YesNo, default='No')

    def __str__(self):
        return self.name

class LedgerGroup(models.Model):
    """
    Ledger Group Master
    """

    group_name = models.CharField(max_length=50)
    group_base = models.ForeignKey(GroupBase, on_delete=models.DO_NOTHING, related_name='base_group', default=1)

    def __str__(self):
        return self.group_name

class LedgerMaster(models.Model):
    """
    Ledger Master
    """
    ledger_name = models.CharField(max_length=80)  # unique together with company using meta
    ledger_group …

我正在使用 django 执行博客应用程序..

每当用户看到特定博客时，无论是注册用户还是非注册用户，我都想跟踪页面查看次数...

并且还想根据查看次数显示查看次数最多的博客..

谁能帮我解决这个..

谢谢

在我的模型中，我想通过覆盖保存方法来格式化图像字段

我在我的模型中做到了这一点

from PIL import Image as Img
from io import StringIO
from django.core.files.uploadedfile import InMemoryUploadedFile


class Blog(models.Model):
    Blog_image= models.ImageField(upload_to="...", blank=True)

    def save(self, *args, **kwargs):
    if self.Blog_image:
        image = Img.open(StringIO.StringIO(self.Blog_image.read()))
        image.thumbnail((900,300), Img.ANTIALIAS)
        output = StringIO.StringIO()
        image.save(output, format='JPEG', quality=150)
        output.seek(0)
        self.Blog_image = InMemoryUploadedFile(output,'ImageField', "%s.jpg" %self.Blog_image.name, 'image/jpeg', output.len, None)
    super(Blog, self).save(*args, **kwargs)

但是得到这个属性错误

AttributeError : type object '_io.StringIO' has no attribute 'StringIO'

谁能解释我为什么会收到这个错误？？？

我的python版本是3.6.4

我的 Django 版本是 2.0.7

这是型号:

class Purchase(models.Model):
    date           = models.DateField(default=datetime.date.today,blank=False, null=True)
    total_purchase = models.DecimalField(max_digits=10,decimal_places=2,blank=True, null=True)

我想在特定的日期范围内执行一个月份的"total_purchase"计算,如果一个月内没有购买,则总购买量应该是上个月的购买价值.如果在两个月内购买,那么总购买量会增加那两个......

例:

假设用户给出的日期范围是从4月到11月.

如果4月份购买2800美元,8月份购买5000美元,10月份购买6000美元.

然后输出将是这样的:

April      2800
May        2800
June       2800
July       2800
August     7800  #(2800 + 5000)
September  7800
October    13800 #(7800 + 6000)
November   13800

知道如何在django查询中执行此操作吗？

谢谢

根据雷德尔米兰达先生的回答.我做了以下事情

import calendar
import collections
import dateutil

start_date = datetime.date(2018, 4, 1)
end_date = datetime.date(2019, 3, 31)

results = collections.OrderedDict()

result = Purchase.objects.filter(date__gte=start_date, date__lt=end_date).annotate(real_total = Case(When(Total_Purchase__isnull=True, then=0),default=F('tal_Purchase')))

date_cursor = start_date

while date_cursor < end_date:
    month_partial_total = result.filter(date__month=date_cursor.month).agggate(partial_total=Sum('real_total'))['partial_total']

    results[date_cursor.month] = month_partial_total …

Traceback (most recent call last):
  File "/Users/sparshkedia/Desktop/task/venv/lib/python3.6/site-packages/django/core/serializers/json.py", line 69, in Deserializer
    yield from PythonDeserializer(objects, **options)
  File "/Users/sparshkedia/Desktop/task/venv/lib/python3.6/site-packages/django/core/serializers/python.py", line 91, in Deserializer
    Model = _get_model(d["model"])
KeyError: 'model'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/sparshkedia/Desktop/task/venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
    utility.execute()
  File "/Users/sparshkedia/Desktop/task/venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 375, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/sparshkedia/Desktop/task/venv/lib/python3.6/site-packages/django/core/management/base.py", line 316, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Users/sparshkedia/Desktop/task/venv/lib/python3.6/site-packages/django/core/management/base.py", line 353, in execute
    output = self.handle(*args, …

我收到以下错误：

Traceback:

 File "C:\Users\HP\GST\lib\site-packages\django\core\handlers\exception.py" 
 in inner
 35.             response = get_response(request)

 File "C:\Users\HP\GST\lib\site-packages\django\core\handlers\base.py" in 
  _get_response
  128.                 response = self.process_exception_by_middleware(e, 
 request)

 File "C:\Users\HP\GST\lib\site-packages\django\core\handlers\base.py" in 
 _get_response
 126.                 response = wrapped_callback(request, *callback_args, 
 **callback_kwargs)

  File "C:\Users\HP\Desktop\erpcloud\accounts\views.py" in change_password
   31.         if form.is_valid():

 File "C:\Users\HP\GST\lib\site-packages\django\forms\forms.py" in is_valid
 179.         return self.is_bound and not self.errors

File "C:\Users\HP\GST\lib\site-packages\django\forms\forms.py" in errors
 174.             self.full_clean()

 File "C:\Users\HP\GST\lib\site-packages\django\forms\forms.py" in 
 full_clean
  376.         self._clean_fields()

 File "C:\Users\HP\GST\lib\site-packages\django\forms\forms.py" in 
_clean_fields
 397.                     value = getattr(self, 'clean_%s' % name)()

  File "C:\Users\HP\GST\lib\site-packages\django\contrib\auth\forms.py" in 
 clean_old_password
  366.         if not self.user.check_password(old_password):

 File "C:\Users\HP\GST\lib\site-packages\django\contrib\auth\models.py" in …

当用户注册我的应用程序时，当他到达个人资料页面时收到此错误

 'ValueError at /profile/:The 'image' attribute has no file associated with 
  it.'

这是我的个人资料模型：

class Profile(models.Model):
Full_Name = models.CharField(max_length=32,blank=True)
Name = models.OneToOneField(settings.AUTH_USER_MODEL,on_delete=models.CASCADE)
E_mail = models.EmailField(max_length=70,blank=True)
Qualification = models.CharField(max_length=32,blank=True)
Permanant_Address = models.TextField(blank=True)
image = models.ImageField(upload_to='user_images', null=True, blank=True)

def __str__(self):
    return str(self.Name)


def get_absolute_url(self):
    return reverse("userprofile:profiledetail")

@property
def image_url(self):
    if self.image and hasattr(self.image, 'url'):
        return self.image_url

这是我的表格：

class profileform(forms.ModelForm)"


class Meta:
    model = Profile
    fields = ('Full_Name','Name', 'E_mail','Qualification','Permanant_Address','image')

这是我的观点：

from django.shortcuts import render
from django.views.generic import DetailView,UpdateView
from django.contrib.auth.mixins import LoginRequiredMixin
from userprofile.models …

我正在开发一个会计应用程序...

我有一个名为“组”的模型，我想在特定公司内制作它......

我的意思是不同的公司会有不同的组

所以，我在列表视图中尝试过类似的事情

class group1ListView(LoginRequiredMixin,ListView):
    model = group1

    def get_queryset(self, pk):
        company_details = get_object_or_404(company, pk=pk)
        return self.model.objects.all().filter(Q(User=self.request.user) & Q(Company=company_details.id))

用户和公司字段通过我的 group1 模型中的外键相关。

但出现此错误：

TypeError get_queryset() 缺少 1 个必需的位置参数：'pk'

谁能告诉我我在这方面做错了什么？

谢谢

我有一个decorater，如果id = 1的产品未激活，它可以防止用户访问url。我想创建与此类似的mixin。

这是我的设计师：

from django.core.exceptions import PermissionDenied
from ecommerce_integration.models import Product 



def product_1_activation(function):
    def wrap(request, *args, **kwargs):
        products = Product.objects.filter(pk=1, activate=True)
        if products:
            return function(request, *args, **kwargs)
        else:
            raise PermissionDenied
    wrap.__doc__ = function.__doc__
    wrap.__name__ = function.__name__
    return wrap

任何想法如何创建类似于上述decorater的自定义混合。

实际上，我想为基于类的视图创建mixin。

有人可以帮我吗？

谢谢