Django raises some Django specific exceptions as well as many standard Python exceptions.
Django core exception classes are defined in django.core.exceptions.
The DoesNotExist exception is raised when an object is not found for the given parameters of a query. Django provides a DoesNotExist exception as an attribute of each model class to identify the class of object that could not be found and to allow you to catch a particular model class with try/except.
The base class for DoesNotExist exceptions; a try/except for ObjectDoesNotExist will catch DoesNotExist exceptions for all models.
See get() for further information on ObjectDoesNotExist and DoesNotExist.
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.
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:
If a SuspiciousOperation exception reaches the 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.core.urlresolvers 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:
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.
URL Resolver exceptions are defined in django.core.urlresolvers.
The Resolver404 exception is raised by django.core.urlresolvers.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.core.urlresolvers when a matching URL in your URLconf cannot be identified based on the parameters supplied.
Database exceptions are provided in django.db.
Django wraps the standard database exceptions so that your Django code has a guaranteed common implementation of these classes.
The Django wrappers for database exceptions behave exactly the same as the underlying database exceptions. See PEP 249, the Python Database API Specification v2.0, for further information.
As per PEP 3134, a __cause__ attribute is set with the original (underlying) database exception, allowing access to any additional information provided. (Note that this attribute is available under both Python 2 and Python 3, although PEP 3134 normally only applies to Python 3.)
Previous versions of Django only wrapped DatabaseError and IntegrityError, and did not provide __cause__.
Raised to prevent deletion of referenced objects when using django.db.models.PROTECT. models.ProtectedError is a subclass of IntegrityError.
Http exceptions are provided in django.http.
The UnreadablePostError is raised when a user cancels an upload.
Transaction exceptions are defined in django.db.transaction.
The TransactionManagementError is raised for any and all problems related to database transactions.
Django raises built-in Python exceptions when appropriate as well. See the Python documentation for further information on the built-in exceptions.
Jul 20, 2015