Django Exceptions

Django core exception classes are defined in .

• exception AppRegistryNotReady[源代码]
• This exception is raised when attempting to use models before the apploading process, which initializes the ORM, iscomplete.

ObjectDoesNotExist

• exception ObjectDoesNotExist[源代码]
• The base class for DoesNotExist exceptions;a try/except for ObjectDoesNotExist will catch exceptions for all models.

See get() for further informationon and DoesNotExist.

EmptyResultSet

• exception EmptyResultSet[源代码]
• EmptyResultSet may be raised during query generation if a query won'treturn any results. Most Django projects won't encounter this exception,but it might be useful for implementing custom lookups and expressions.

FieldDoesNotExist

• exception FieldDoesNotExist

MultipleObjectsReturned

• exception MultipleObjectsReturned[源代码]
• The MultipleObjectsReturned exception is raised by a query if onlyone object is expected, but multiple objects are returned. A base versionof this exception is provided in ; each modelclass contains a subclassed version that can be used to identify thespecific object type that has returned multiple objects.

See get() for further information.

• exception SuspiciousOperation
• • DisallowedHost
  • DisallowedModelAdminLookup
  • DisallowedModelAdminToField
  • DisallowedRedirect
  • InvalidSessionKey
  • RequestDataTooBig
  • SuspiciousFileOperation
  • SuspiciousSession
  • TooManyFieldsSent
    If a SuspiciousOperation exception reaches the WSGI handler level it islogged at the Error level and results ina . See the loggingdocumentation for more information.

PermissionDenied

• exception PermissionDenied[源代码]
• The PermissionDenied exception is raised when a user does not havepermission to perform the action requested.

ViewDoesNotExist

• exception ViewDoesNotExist[源代码]
• The ViewDoesNotExist exception is raised by when a requested view does not exist.

MiddlewareNotUsed

• exception MiddlewareNotUsed
• The exception is raised when a middleware is notused in the server configuration.

ImproperlyConfigured

• exception ImproperlyConfigured
• The exception is raised when Django issomehow improperly configured — for example, if a value in settings.pyis incorrect or unparseable.

• exception FieldError[源代码]

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

  • A field in a model clashes with a field of the same name from anabstract 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 queryparameters
  • A join is not permitted on the specified field
  • A field name is invalid
  • A query contains invalid order_by arguments

ValidationError

• exception ValidationError[源代码]

NON_FIELD_ERRORS

• NON_FIELD_ERRORS
• ValidationErrors that don't belong to a particular field in a formor model are classified as NON_FIELD_ERRORS. This constant is usedas a key in dictionaries that otherwise map fields to their respectivelist of errors.

URL Resolver exceptions

URL Resolver exceptions are defined in django.urls.

Resolver404

• exception Resolver404[源代码]
• The Resolver404 exception is raised by if the path passed to resolve() doesn'tmap to a view. It's a subclass of django.http.Http404.

NoReverseMatch

• exception [源代码]
• The NoReverseMatch exception is raised by when amatching URL in your URLconf cannot be identified based on the parameterssupplied.

Database exceptions may be imported from django.db.

• exception Error[源代码]
• exception InterfaceError[源代码]
• exception DatabaseError[源代码]
• exception DataError[源代码]
• exception OperationalError[源代码]
• exception IntegrityError[源代码]
• exception InternalError[源代码]
• exception ProgrammingError[源代码]
• exception NotSupportedError[源代码]
• The Django wrappers for database exceptions behave exactly the same asthe underlying database exceptions. See PEP 249, the Python Database APISpecification v2.0, for further information.

As per , a cause attribute is set with the original(underlying) database exception, allowing access to any additionalinformation provided.

• exception models.ProtectedError
• Raised to prevent deletion of referenced objects when using. models.ProtectedError is a subclassof .

Http Exceptions

Http exceptions may be imported from django.http.

UnreadablePostError

• exception UnreadablePostError[源代码]
• UnreadablePostError is raised when a user cancels an upload.

Transaction exceptions are defined in django.db.transaction.

• exception TransactionManagementError
• is raised for any and all problemsrelated to database transactions.

Testing Framework Exceptions

RedirectCycleError

• exception client.RedirectCycleError
• is raised when the test client detects aloop or an overly long chain of redirects.

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