To fix Python Django DB Settings ‘Improperly Configured’ Error, we can load the settings with settings.configure.
For instance, we write
from django.conf import settings
settings.configure()
to call settings.configure to load the settings for our Python Django app.
To dynamically compose an OR query filter in Python Django, we can call filter with Q objects combined with |.
For instance, we write
values = [1,2,3]
queries = [Q(pk=value) for value in values]
query = queries.pop()
for item in queries:
query |= item
Article.objects.filter(query)
to create the queries list with a list of Q object with the conditions we want to filter by.
Then we loop through the queries to combine them with |= into query.
Finally, we call filter with query to filter by all the conditions.
To use use different serializers in the same ModelViewSet with Python Django rest framework, we can add the get_serializer_class into a mixin.
For instance, we write
def get_serializer_class(self):
try:
return self.serializer_action_classes[self.action]
except (KeyError, AttributeError):
return super(MultiSerializerViewSetMixin, self).get_serializer_class()
to add the get_serializer_class method.
In it, we look for serializer class in self.serializer_action_classes, which should be a dict mapping action name (key) to serializer class (value).
And if there’s no entry for that action then just fallback to the regular get_serializer_class lookup by returning self.serializer_class, DefaultSerializer.
To create email templates with Python Django, we use the EmailMultiAlternatives class.
For instance, we write
from django.core.mail import EmailMultiAlternatives
subject, from_email, to = 'hello', 'from@example.com', 'to@example.com'
text_content = 'This is an important message.'
html_content = '<p>This is an <strong>important</strong> message.</p>'
msg = EmailMultiAlternatives(subject, text_content, from_email, [to])
msg.attach_alternative(html_content, "text/html")
msg.send()
to create a EmailMultiAlternatives instance with the subject, text_content, from_email, and to.
And then we add HTML content by calling attach_alternative with html_content and 'text/html'.
Finally, we call send to send the email.
To fix Python Django stops working with RuntimeError: populate() isn’t reentrant, we can make a change to django/apps/registry.py.
To fix this, in django/apps/registry.py, we change
raise RuntimeError("populate() isn't reentrant")
with
self.app_configs = {}