Django raises some Django specific exceptions as well as many standard Python exceptions.
Django core exception classes are defined in django.core.exceptions
.
DoesNotExist
¶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
.
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
.
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
[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:
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.
PermissionDenied
[source]¶The PermissionDenied
exception is raised when a user does not have
permission to perform the action requested.
ViewDoesNotExist
[source]¶The ViewDoesNotExist
exception is raised by
django.core.urlresolvers
when a requested view does not exist.
MiddlewareNotUsed
[source]¶The MiddlewareNotUsed
exception is raised when a middleware is not
used in the server configuration.
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
[source]¶The FieldError
exception is raised when there is a problem with a
model field. This can happen for several reasons:
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.core.urlresolvers
.
Resolver404
[source]¶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
NoReverseMatch
[source]¶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__
.
models.
ProtectedError
¶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
.
UnreadablePostError
[source]¶The UnreadablePostError
is raised when a user cancels an upload.
Transaction exceptions are defined in django.db.transaction
.
TransactionManagementError
[source]¶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.
Feb 24, 2017