Django raises some of its own exceptions as well as standard Python exceptions.
Django core exception classes are defined in django.core.exceptions.
AppRegistryNotReady¶AppRegistryNotReady[source]¶This exception is raised when attempting to use models before the app loading process, which initializes the ORM, is complete.
ObjectDoesNotExist¶ObjectDoesNotExist[source]¶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.
EmptyResultSet¶EmptyResultSet[source]¶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.
In older versions, it’s only importable from django.db.models.sql.
FieldDoesNotExist¶MultipleObjectsReturned¶MultipleObjectsReturned[source]¶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¶SuspiciousOperation[source]¶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:
DisallowedHostDisallowedModelAdminLookupDisallowedModelAdminToFieldDisallowedRedirectInvalidSessionKeyRequestDataTooBigSuspiciousFileOperationSuspiciousMultipartFormSuspiciousSessionTooManyFieldsSentIf 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.
PermissionDenied¶PermissionDenied[source]¶The PermissionDenied exception is raised when a user does not have
permission to perform the action requested.
ViewDoesNotExist¶ViewDoesNotExist[source]¶The ViewDoesNotExist exception is raised by
django.urls when a requested view does not exist.
MiddlewareNotUsed¶MiddlewareNotUsed[source]¶The MiddlewareNotUsed exception is raised when a middleware is not
used in the server configuration.
ImproperlyConfigured¶ImproperlyConfigured[source]¶The ImproperlyConfigured exception is raised when Django is
somehow improperly configured – for example, if a value in settings.py
is incorrect or unparseable.
FieldError¶FieldError[source]¶The FieldError exception is raised when there is a problem with a
model field. This can happen for several reasons:
ValidationError¶ValidationError[source]¶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.urls.
Deprecated since version 1.10: In older versions, these exceptions are located in
django.core.urlresolvers. Importing from the old location will continue
to work until Django 2.0.
Resolver404¶Resolver404[source]¶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.
NoReverseMatch¶NoReverseMatch[source]¶The NoReverseMatch exception is raised by django.urls when a
matching URL in your URLconf cannot be identified based on the parameters
supplied.
Database exceptions may be imported from 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. To avoid unexpected differences with Python 3, Django will also
ensure that the exception made available via __cause__ has a usable
__traceback__ attribute.)
The __traceback__ attribute described above was added.
models.ProtectedError¶Raised to prevent deletion of referenced objects when using
django.db.models.PROTECT. models.ProtectedError is a subclass
of IntegrityError.
Http exceptions may be imported from django.http.
UnreadablePostError¶UnreadablePostError[source]¶UnreadablePostError is raised when a user cancels an upload.
Transaction exceptions are defined in django.db.transaction.
TransactionManagementError¶TransactionManagementError[source]¶TransactionManagementError is raised for any and all problems
related to database transactions.
Exceptions provided by the django.test package.
RedirectCycleError¶client.RedirectCycleError¶RedirectCycleError is raised when the test client detects a
loop or an overly long chain of redirects.
Django raises built-in Python exceptions when appropriate as well. See the Python documentation for further information on the Built-in Exceptions.
Jun 14, 2020