mirror of
https://github.com/django/django.git
synced 2024-11-18 07:26:04 +00:00
9f4e031bd3
When Django reraises an exception, it sets the __cause__ attribute even in Python 2, mimicking Python's 3 behavior for "raise Foo from Bar". However, Python 3 also ensures that all exceptions have a __traceback__ attribute and thus the "traceback2" Python 2 module (backport of Python 3's "traceback" module) relies on the fact that whenever you have a __cause__ attribute, the recorded exception also has a __traceback__ attribute. This is breaking testtools which is using traceback2 (see https://github.com/testing-cabal/testtools/issues/162). This commit fixes this inconsistency by ensuring that Django sets the __traceback__ attribute on any exception stored in a __cause__ attribute of a reraised exception.
262 lines
7.8 KiB
Plaintext
262 lines
7.8 KiB
Plaintext
=================
|
|
Django Exceptions
|
|
=================
|
|
|
|
Django raises some of its own exceptions as well as standard Python exceptions.
|
|
|
|
Django Core Exceptions
|
|
======================
|
|
|
|
.. module:: django.core.exceptions
|
|
:synopsis: Django core exceptions
|
|
|
|
Django core exception classes are defined in ``django.core.exceptions``.
|
|
|
|
``ObjectDoesNotExist``
|
|
----------------------
|
|
|
|
.. exception:: ObjectDoesNotExist
|
|
|
|
The base class for :exc:`~django.db.models.Model.DoesNotExist` exceptions;
|
|
a ``try/except`` for ``ObjectDoesNotExist`` will catch
|
|
:exc:`~django.db.models.Model.DoesNotExist` exceptions for all models.
|
|
|
|
See :meth:`~django.db.models.query.QuerySet.get()` for further information
|
|
on :exc:`ObjectDoesNotExist` and :exc:`~django.db.models.Model.DoesNotExist`.
|
|
|
|
``FieldDoesNotExist``
|
|
---------------------
|
|
|
|
.. exception:: FieldDoesNotExist
|
|
|
|
The ``FieldDoesNotExist`` exception is raised by a model's
|
|
``_meta.get_field()`` method when the requested field does not exist on the
|
|
model or on the model's parents.
|
|
|
|
``MultipleObjectsReturned``
|
|
---------------------------
|
|
|
|
.. exception:: MultipleObjectsReturned
|
|
|
|
The :exc:`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 :mod:`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 :meth:`~django.db.models.query.QuerySet.get()` for further information.
|
|
|
|
``SuspiciousOperation``
|
|
-----------------------
|
|
|
|
.. exception:: SuspiciousOperation
|
|
|
|
The :exc:`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:
|
|
|
|
* ``DisallowedHost``
|
|
* ``DisallowedModelAdminLookup``
|
|
* ``DisallowedModelAdminToField``
|
|
* ``DisallowedRedirect``
|
|
* ``InvalidSessionKey``
|
|
* ``SuspiciousFileOperation``
|
|
* ``SuspiciousMultipartForm``
|
|
* ``SuspiciousSession``
|
|
|
|
If a ``SuspiciousOperation`` exception reaches the WSGI handler level it is
|
|
logged at the ``Error`` level and results in
|
|
a :class:`~django.http.HttpResponseBadRequest`. See the :doc:`logging
|
|
documentation </topics/logging/>` for more information.
|
|
|
|
``PermissionDenied``
|
|
--------------------
|
|
|
|
.. exception:: PermissionDenied
|
|
|
|
The :exc:`PermissionDenied` exception is raised when a user does not have
|
|
permission to perform the action requested.
|
|
|
|
``ViewDoesNotExist``
|
|
--------------------
|
|
|
|
.. exception:: ViewDoesNotExist
|
|
|
|
The :exc:`ViewDoesNotExist` exception is raised by
|
|
:mod:`django.core.urlresolvers` when a requested view does not exist.
|
|
|
|
``MiddlewareNotUsed``
|
|
---------------------
|
|
|
|
.. exception:: MiddlewareNotUsed
|
|
|
|
The :exc:`MiddlewareNotUsed` exception is raised when a middleware is not
|
|
used in the server configuration.
|
|
|
|
``ImproperlyConfigured``
|
|
------------------------
|
|
|
|
.. exception:: ImproperlyConfigured
|
|
|
|
The :exc:`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 :exc:`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 :exc:`ValidationError` exception is raised when data fails form or
|
|
model field validation. For more information about validation, see
|
|
:doc:`Form and Field Validation </ref/forms/validation>`,
|
|
:ref:`Model Field Validation <validating-objects>` and the
|
|
:doc:`Validator Reference </ref/validators>`.
|
|
|
|
``NON_FIELD_ERRORS``
|
|
~~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. data:: NON_FIELD_ERRORS
|
|
|
|
``ValidationError``\s that don't belong to a particular field in a form
|
|
or model are classified as ``NON_FIELD_ERRORS``. This constant is used
|
|
as a key in dictionaries that otherwise map fields to their respective
|
|
list of errors.
|
|
|
|
.. currentmodule:: django.core.urlresolvers
|
|
|
|
URL Resolver exceptions
|
|
=======================
|
|
|
|
URL Resolver exceptions are defined in ``django.core.urlresolvers``.
|
|
|
|
``Resolver404``
|
|
---------------
|
|
|
|
.. exception:: Resolver404
|
|
|
|
The :exc:`Resolver404` exception is raised by
|
|
:func:`django.core.urlresolvers.resolve()` if the path passed to
|
|
``resolve()`` doesn't map to a view. It's a subclass of
|
|
:class:`django.http.Http404`.
|
|
|
|
``NoReverseMatch``
|
|
------------------
|
|
|
|
.. exception:: NoReverseMatch
|
|
|
|
The :exc:`NoReverseMatch` exception is raised by
|
|
:mod:`django.core.urlresolvers` when a matching URL in your URLconf
|
|
cannot be identified based on the parameters supplied.
|
|
|
|
.. currentmodule:: django.db
|
|
|
|
Database Exceptions
|
|
===================
|
|
|
|
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.
|
|
|
|
.. exception:: Error
|
|
.. exception:: InterfaceError
|
|
.. exception:: DatabaseError
|
|
.. exception:: DataError
|
|
.. exception:: OperationalError
|
|
.. exception:: IntegrityError
|
|
.. exception:: InternalError
|
|
.. exception:: ProgrammingError
|
|
.. exception:: NotSupportedError
|
|
|
|
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.)
|
|
|
|
.. versionchanged:: 1.10
|
|
|
|
The ``__traceback__`` attribute described above was added.
|
|
|
|
.. exception:: models.ProtectedError
|
|
|
|
Raised to prevent deletion of referenced objects when using
|
|
:attr:`django.db.models.PROTECT`. :exc:`models.ProtectedError` is a subclass
|
|
of :exc:`IntegrityError`.
|
|
|
|
.. currentmodule:: django.http
|
|
|
|
Http Exceptions
|
|
===============
|
|
|
|
Http exceptions may be imported from ``django.http``.
|
|
|
|
``UnreadablePostError``
|
|
-----------------------
|
|
|
|
.. exception:: UnreadablePostError
|
|
|
|
:exc:`UnreadablePostError` is raised when a user cancels an upload.
|
|
|
|
Transaction Exceptions
|
|
======================
|
|
|
|
.. currentmodule:: django.db.transaction
|
|
|
|
Transaction exceptions are defined in ``django.db.transaction``.
|
|
|
|
``TransactionManagementError``
|
|
------------------------------
|
|
|
|
.. exception:: TransactionManagementError
|
|
|
|
:exc:`TransactionManagementError` is raised for any and all problems
|
|
related to database transactions.
|
|
|
|
.. currentmodule:: django.test
|
|
|
|
Testing Framework Exceptions
|
|
============================
|
|
|
|
Exceptions provided by the ``django.test`` package.
|
|
|
|
``RedirectCycleError``
|
|
----------------------
|
|
|
|
.. exception:: client.RedirectCycleError
|
|
|
|
:exc:`~client.RedirectCycleError` is raised when the test client detects a
|
|
loop or an overly long chain of redirects.
|
|
|
|
Python Exceptions
|
|
=================
|
|
|
|
Django raises built-in Python exceptions when appropriate as well. See the
|
|
Python documentation for further information on the :ref:`bltin-exceptions`.
|