Author: John Au-Yeung

Sometimes, we want to redirect logged in users from login page with Python Django.

In this article, we’ll look at how to redirect logged in users from login page with Python Django.

How to redirect logged in users from login page with Python Django?

To redirect logged in users from login page with Python Django, we can set the redirect_authenticated_user argument when we call as_view.

For instance, we write

from django.contrib.auth import views as auth_views
from django.urls import path

urlpatterns = [
    path('login/', auth_views.LoginView.as_view(redirect_authenticated_user=True), name='login'),
]

to call auth_views.LoginView.as_view with the redirect_authenticated_user to True to redirect users from the login page to the destination once the user is logged in.

Conclusion

To redirect logged in users from login page with Python Django, we can set the redirect_authenticated_user argument when we call as_view.

Sometimes, we want to split models.py into several files with Python Django.

In this article, we’ll look at how to split models.py into several files with Python Django.

How to split models.py into several files with Python Django?

To split models.py into several files with Python Django, we can put the model files in the models folder in our app folder.

And we add the __init__.py file into the root of the models folder.

For instance, we can have this structure in our app

app1/
    views.py
    __init__.py
    models/
        __init__.py
        model1.py
        model2.py

We add __init__.py into app1/models and we add the model class files inside app1/models.

Conclusion

To split models.py into several files with Python Django, we can put the model files in the models folder in our app folder.

And we add the __init__.py file into the root of the models folder.

Sometimes, we want to set up custom middleware in Python Django.

In this article, we’ll look at how to set up custom middleware in Python Django.

How to set up custom middleware in Python Django?

To set up custom middleware in Python Django, we create our own class.

For instance, we write

class CustomMiddleware(object):
    def __init__(self, get_response):
        #...
        self.get_response = get_response

    def __call__(self, request):
        #...
        response = self.get_response(request)
        return response

    def process_view(self, request, view_func, view_args, view_kwargs):
        #...
        return None

    def process_exception(self, request, exception):
        #...
        return None

    def process_template_response(self, request, response):
        #...
        return response

to create the CustomMiddleware class.

We add the __init__ method to initialize the middleware.

__call__ is called on each request.

process_view is called before Django calls the view.

process_exception is called when a view raises an exception.

And process_template_response is called after the view finished executing.

Then we activate our middleware by putting it in the MIDDLEWARE list in the settings.py file.

We write

MIDDLEWARE = [
    # ...
    # Add your custom middleware
    'path.to.your.middleware.CustomMiddleware',
]

to add our CustomMiddleware class into the list.

Conclusion

To set up custom middleware in Python Django, we create our own class.

Sometimes, we want to access session variables from within a template with Python Django.

In this article, we’ll look at how to access session variables from within a template with Python Django.

How to access session variables from within a template with Python Django?

To access session variables from within a template with Python Django, we can use the request.session property.

For instance, we write

{{ request.session.name }}

to get the name value from request.session in our template.

Conclusion

To access session variables from within a template with Python Django, we can use the request.session property.

Sometimes, we want to fix ‘You are trying to add a non-nullable field ‘new_field’ to userprofile without a default’ error with Python Django.

In this article, we’ll look at how to fix ‘You are trying to add a non-nullable field ‘new_field’ to userprofile without a default’ error with Python Django.

How to fix ‘You are trying to add a non-nullable field ‘new_field’ to userprofile without a default’ error with Python Django?

To fix ‘You are trying to add a non-nullable field ‘new_field’ to userprofile without a default’ error with Python Django, we can set a default value for the non-nullable field.

For instance, we write

new_field = models.CharField(max_length=140, default='DEFAULT VALUE')

to set the default value of new_field to 'DEFAULT VALUE' by calling the CharField constructor with the default argument.

Conclusion

To fix ‘You are trying to add a non-nullable field ‘new_field’ to userprofile without a default’ error with Python Django, we can set a default value for the non-nullable field.