Django ExceptionsLink to this heading#

This exception is raised when attempting to use models before the app loading process, which initializes the ORM, is complete.

The base class for Model.DoesNotExist exceptions. A try/except for ObjectDoesNotExist will catch DoesNotExist exceptions for all models.

See get().

The base class for Model.NotUpdated exceptions. A try/except for ObjectNotUpdated will catch NotUpdated exceptions for all models.

See save().

EmptyResultSet may be raised during query generation if a query won’t return any results. Most Django projects won’t encounter this exception, but it might be useful for implementing custom lookups and expressions.

FullResultSet may be raised during query generation if a query will match everything. Most Django projects won’t encounter this exception, but it might be useful for implementing custom lookups and expressions.

The FieldDoesNotExist exception is raised by a model’s _meta.get_field() method when the requested field does not exist on the model or on the model’s parents.

The base class for Model.MultipleObjectsReturned exceptions. A try/except for MultipleObjectsReturned will catch MultipleObjectsReturned exceptions for all models.

See get().

The SuspiciousOperation exception is raised when a user has performed an operation that should be considered suspicious from a security perspective, such as tampering with a session cookie. Subclasses of SuspiciousOperation include:

• DisallowedHost

• DisallowedModelAdminLookup

• DisallowedModelAdminToField

• DisallowedRedirect

• InvalidSessionKey

• RequestDataTooBig

• SuspiciousFileOperation

• SuspiciousMultipartForm

• SuspiciousSession

• TooManyFieldsSent

• TooManyFilesSent

If a SuspiciousOperation exception reaches the ASGI/WSGI handler level it is logged at the Error level and results in a HttpResponseBadRequest. See the logging documentation for more information.

The PermissionDenied exception is raised when a user does not have permission to perform the action requested.

The ViewDoesNotExist exception is raised by django.urls when a requested view does not exist.

The MiddlewareNotUsed exception is raised when a middleware is not used in the server configuration.

The ImproperlyConfigured exception is raised when Django is somehow improperly configured – for example, if a value in settings.py is incorrect or unparseable.

The FieldError exception is raised when there is a problem with a model field. This can happen for several reasons:

• A field in a model clashes with a field of the same name from an abstract base class

• An infinite loop is caused by ordering

• A keyword cannot be parsed from the filter parameters

• A field cannot be determined from a keyword in the query parameters

• A join is not permitted on the specified field

• A field name is invalid

• A query contains invalid order_by arguments

The ValidationError exception is raised when data fails form or model field validation. For more information about validation, see Form and Field Validation, Model Field Validation and the Validator Reference.

The BadRequest exception is raised when the request cannot be processed due to a client error. If a BadRequest exception reaches the ASGI/WSGI handler level it results in a HttpResponseBadRequest.

The RequestAborted exception is raised when an HTTP body being read in by the handler is cut off midstream and the client connection closes, or when the client does not send data and hits a timeout where the server closes the connection.

It is internal to the HTTP handler modules and you are unlikely to see it elsewhere. If you are modifying HTTP handling code, you should raise this when you encounter an aborted request to make sure the socket is closed cleanly.

The SynchronousOnlyOperation exception is raised when code that is only allowed in synchronous Python code is called from an asynchronous context (a thread with a running asynchronous event loop). These parts of Django are generally heavily reliant on thread-safety to function and don’t work correctly under coroutines sharing the same thread.

If you are trying to call code that is synchronous-only from an asynchronous thread, then create a synchronous thread and call it in that. You can accomplish this is with asgiref.sync.sync_to_async().

The Resolver404 exception is raised by resolve() if the path passed to resolve() doesn’t map to a view. It’s a subclass of django.http.Http404.

The NoReverseMatch exception is raised by django.urls when a matching URL in your URLconf cannot be identified based on the parameters supplied.

UnreadablePostError is raised when a user cancels an upload.

SessionInterrupted is raised when a session is destroyed in a concurrent request. It’s a subclass of BadRequest.

TransactionManagementError is raised for any and all problems related to database transactions.

RedirectCycleError is raised when the test client detects a loop or an overly long chain of redirects.