Django documentation

Django Exceptions

Django raises some Django specific exceptions as well as many standard Python exceptions.

Django-specific Exceptions

ObjectDoesNotExist and DoesNotExist

exception DoesNotExist
exception ObjectDoesNotExist

The DoesNotExist exception is raised when an object is not found for the given parameters of a query.

ObjectDoesNotExist is defined in django.core.exceptions. DoesNotExist is a subclass of the base ObjectDoesNotExist exception that is provided on every model class as a way of identifying the specific type of object that could not be found.

See get() for further information on ObjectDoesNotExist and DoesNotExist.

MultipleObjectsReturned

exception MultipleObjectsReturned

The MultipleObjectsReturned exception is raised by a query if only one object is expected, but multiple objects are returned. A base version of this exception is provided in django.core.exceptions; each model class contains a subclassed version that can be used to identify the specific object type that has returned multiple objects.

See get() for further information.

SuspiciousOperation

exception SuspiciousOperation

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.

PermissionDenied

exception PermissionDenied

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

ViewDoesNotExist

exception ViewDoesNotExist

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

MiddlewareNotUsed

exception MiddlewareNotUsed

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

ImproperlyConfigured

exception ImproperlyConfigured

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

FieldError

exception FieldError

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

ValidationError

exception ValidationError

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.

NoReverseMatch

exception NoReverseMatch

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

Database Exceptions

Django wraps the standard database exceptions DatabaseError and IntegrityError so that your Django code has a guaranteed common implementation of these classes. These database exceptions are provided in django.db.

exception DatabaseError
exception IntegrityError

The Django wrappers for database exceptions behave exactly the same as the underlying database exceptions. See PEP 249 - Python Database API Specification v2.0 for further information.

Transaction Exceptions

exception TransactionManagementError

The TransactionManagementError is raised for any and all problems related to database transactions. It is available from django.db.transaction.

Python Exceptions

Django raises built-in Python exceptions when appropriate as well. See the Python documentation for further information on the built-in exceptions.

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