pylint-django 0.10.0

pylint-django
=============

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About
-----

``pylint-django`` is a `Pylint <http://pylint.org>`__ plugin for improving code
analysis when analysing code using Django. It is also used by the
`Prospector <https://github.com/landscapeio/prospector>`__ tool.


Installation
------------

To install::

pip install pylint-django


**WARNING:** ``pylint-django`` will not install ``Django`` by default because
this causes more trouble than good,
`see discussion <https://github.com/PyCQA/pylint-django/pull/132>`__. If you wish
to automatically install the latest version of ``Django`` then::

pip install pylint-django[with_django]

otherwise sort out your testing environment and please **DO NOT** report issues
about missing Django!


Usage
-----

Ensure ``pylint-django`` is installed and on your path and then execute::

pylint --load-plugins pylint_django [..other options..] <path_to_your_sources>


Prospector
----------

If you have ``prospector`` installed, then ``pylint-django`` will already be
installed as a dependency, and will be activated automatically if Django is
detected::

prospector [..other options..]


Features
--------

* Prevents warnings about Django-generated attributes such as
``Model.objects`` or ``Views.request``.
* Prevents warnings when using ``ForeignKey`` attributes ("Instance of
ForeignKey has no <x> member").
* Fixes pylint's knowledge of the types of Model and Form field attributes
* Validates ``Model.__unicode__`` methods.
* ``Meta`` informational classes on forms and models do not generate errors.


Additional plugins
------------------

``pylint_django.checkers.db_performance`` looks for migrations which add new
model fields and these fields have a default value. According to
`Django docs <https://docs.djangoproject.com/en/2.0/topics/migrations/#postgresql>`__
this may have performance penalties especially on large tables. The prefered way
is to add a new DB column with ``null=True`` because it will be created instantly
and then possibly populate the table with the desired default values.

Only the last migration from a sub-directory will be examined!

This plugin is disabled by default! To enable it::

pylint --load-plugins pylint_django --load-plugins pylint_django.checkers.db_performance


Contributing
------------

Please feel free to add your name to the ``CONTRIBUTORS.rst`` file if you want to
be credited when pull requests get merged. You can also add to the
``CHANGELOG.rst`` file if you wish, although we'll also do that when merging.


Tests
-----

The structure of the test package follows that from pylint itself.

It is fairly simple: create a module starting with ``func_`` followed by
a test name, and insert into it some code. The tests will run pylint
against these modules. If the idea is that no messages now occur, then
that is fine, just check to see if it works by running ``scripts/test.sh``.

Ideally, add some pylint error suppression messages to the file to prevent
spurious warnings, since these are all tiny little modules not designed to
do anything so there's no need to be perfect.

It is possible to make tests with expected error output, for example, if
adding a new message or simply accepting that pylint is supposed to warn.
A ``test_file_name.txt`` file contains a list of expected error messages in the
format
``error-type:line number:class name or empty:1st line of detailed error text``.


License
-------

``pylint-django`` is available under the GPLv2 license.

Changelog
=========


Version 0.10.0 (10 April 2018)
-----------------------------

- Remove the compatibility layer for older astroid versions
- Make flake8 happy. Fix
`#102 <https://github.com/PyCQA/pylint-django/issues/102>`__
- Fix: compatibility with Python < 3.6 caused by ``ModuleNotFoundError``
not available on older versions of Python (Juan Rial)
- Show README and CHANGELOG on PyPI. Fix
`#122 <https://github.com/PyCQA/pylint-django/issues/122>`__
- Fix explicit unicode check with ``python_2_unicode_compatible`` base models
(Federico Bond)
- Suppress ``not-an-iterable`` message for 'objects'. Fix
`#117 <https://github.com/PyCQA/pylint-django/issues/117>`__
- Teach pylint_django that ``objects.all()`` is subscriptable. Fix
`#144 <https://github.com/PyCQA/pylint-django/issues/144>`__
- Suppress ``invalid-name`` for ``wsgi.application``. Fix
`#77 <https://github.com/PyCQA/pylint-django/issues/77>`__
- Add test for ``WSGIRequest.context``. Closes
`#78 <https://github.com/PyCQA/pylint-django/issues/78>`__
- Register transforms for ``FileField``. Fix
`#60 <https://github.com/PyCQA/pylint-django/issues/60>`__
- New checker ``pylint_django.checkers.db_performance``.
Enables checking of migrations and reports when there's an
``AddField`` operation with a default value which may slow down applying
migrations on large tables. This may also lead to production tables
being locked while migrations are being applied. Fix
`#118 <https://github.com/PyCQA/pylint-django/issues/118>`__
- Suppress ``no-member`` for ``factory.SubFactory`` objects.
Useful when model factories use ``factory.SubFactory()`` for foreign
key relations.


Version 0.9.4 (12 March 2018)
-----------------------------

- Add an optional dependency on Django
- Fix the ``DjangoInstalledChecker`` so it can actually warn when
Django isn't available
- Fix `#136 <https://github.com/PyCQA/pylint-django/issues/136>`__ by
adding automated build and sanity test scripts

Version 0.9.3 (removed from PyPI)
---------------------------------

- Fix `#133 <https://github.com/PyCQA/pylint-django/issues/133>`__ and
`#134 <https://github.com/PyCQA/pylint-django/issues/134>`__ by
including package data when building wheel and tar.gz packages for
PyPI (Joseph Herlant)

Version 0.9.2 (broken)
----------------------

- Fix `#129 <https://github.com/PyCQA/pylint-django/issues/129>`__ -
Move tests under ``site-packages/pylint_django`` (Mr. Senko)
- Fix `#96 <https://github.com/PyCQA/pylint-django/issues/96>`__ - List
Django as a dependency (Mr. Senko)

Version 0.9.1 (26 Feb 2018)
---------------------------

- Fix `#123 <https://github.com/PyCQA/pylint-django/issues/123>`__ -
Update links after the move to PyCQA (Mr. Senko)
- Add test for Meta class from django\_tables2 (Mr. Senko)
- Fix flake8 complaints (Peter Bittner)
- Add missing .txt and .rc test files to MANIFEST.in (Joseph Herlant)

Version 0.9 (25 Jan 2018)
-------------------------

- Fix `#120 <https://github.com/PyCQA/pylint-django/issues/120>`__ -
TypeError: 'NamesConsumer' object does not support indexing (Simone
Basso)
- Fix `#110 <https://github.com/PyCQA/pylint-django/issues/120>`__ and
`#35 <https://github.com/PyCQA/pylint-django/issues/120>`__ - resolve
ForeignKey models specified as strings instead of class names (Mr.
Senko)

Version 0.8.0 (20 Jan 2018)
---------------------------

- This is the last version to support Python 2. Issues a deprecation
warning!
- `#109 <http://github.com/PyCQA/pylint-django/pull/109>`__, adding
'urlpatterns', 'register', 'app\_name' to good names. Obsoletes
`#111 <http://github.com/PyCQA/pylint-django/pull/111>`__, fixes
`#108 <http://github.com/PyCQA/pylint-django/issues/108>`__ (Vinay
Pai)
- Add 'handler500' to good names (Mr. Senko)
- `#103 <http://github.com/PyCQA/pylint-django/pull/103>`__: Support
factory\_boy's DjangoModelFactory Meta class (Konstantinos
Koukopoulos)
- `#100 <https://github.com/PyCQA/pylint-django/pull/100>`__: Fix
E1101:Instance of '**proxy**\ ' has no 'format' member' when using
.format() on a ugettext\_lazy translation. Fixes
`#80 <https://github.com/PyCQA/pylint-django/issues/80>`__
(canarduck)
- `#99 <https://github.com/PyCQA/pylint-django/pull/99>`__: Add tests
and transforms for DurationField, fixes
`#95 <https://github.com/PyCQA/pylint-django/issues/95>`__ (James M.
Allen)
- `#92 <https://github.com/PyCQA/pylint-django/pull/92>`__: Add json
field to WSGIRequest proxy (sjk4sc)
- `#84 <https://github.com/PyCQA/pylint-django/pull/84>`__: Add support
for django.contrib.postgres.fields and UUIDField (Villiers Strauss)
- Stop testing with older Django versions. Currently testing with
Django 1.11.x and 2.0
- Stop testing on Python 2, no functional changes in the source code
though
- Update tests and require latest version of pylint (>=1.8), fixes
`#53 <https://github.com/PyCQA/pylint-django/issues/53>`__,
`#97 <https://github.com/PyCQA/pylint-django/issues/97>`__
- `#81 <https://github.com/PyCQA/pylint-django/issues/81>`__ Fix
'duplicate-except' false negative for except blocks which catch the
``DoesNotExist`` exception.

Version 0.7.4
-------------

- `#88 <https://github.com/PyCQA/pylint-django/pull/88>`__ Fixed builds
with Django 1.10 (thanks to
`federicobond <https://github.com/federicobond>`__)
- `#91 <https://github.com/PyCQA/pylint-django/pull/91>`__ Fixed race
condition when running with pylint parallel execution mode (thanks to
`jeremycarroll <https://github.com/jeremycarroll>`__)
- `#64 <https://github.com/PyCQA/pylint-django/issues/64>`__ "Meta is
old style class" now suppressed on BaseSerializer too (thanks to
`unklphil <https://github.com/unklphil>`__)
- `#70 <https://github.com/PyCQA/pylint-django/pull/70>`__ Updating to
handle newer pylint/astroid versions (thanks to
`iXce <https://github.com/iXce>`__)

Version 0.7.2
-------------

- `#76 <https://github.com/PyCQA/pylint-django/pull/76>`__ Better
handling of mongoengine querysetmanager
- `#73 <https://github.com/PyCQA/pylint-django/pull/73>`__
`#72 <https://github.com/PyCQA/pylint-django/issues/72>`__ Make package
zip safe to help fix some path problems
- `#68 <https://github.com/PyCQA/pylint-django/pull/68>`__ Suppressed
invalid constant warning for "app\_name" in urls.py
- `#67 <https://github.com/PyCQA/pylint-django/pull/67>`__ Fix
view.args and view.kwargs
- `#66 <https://github.com/PyCQA/pylint-django/issues/66>`__ accessing
\_meta no longer causes a protected-access warning as this is a
public API as of Django 1.8
- `#65 <https://github.com/PyCQA/pylint-django/pull/65>`__ Add support
of mongoengine module.
- `#59 <https://github.com/PyCQA/pylint-django/pull/59>`__ Silence
old-style-class for widget Meta

Version 0.7.1
-------------

- `#52 <https://github.com/PyCQA/pylint-django/issues/52>`__ - Fixed
stupid mistake when using versioninfo

Version 0.7
-----------

- `#51 <https://github.com/PyCQA/pylint-django/issues/51>`__ - Fixed
compatibility with pylint 1.5 / astroid 1.4.1

Version 0.6.1
-------------

- `#43 <https://github.com/PyCQA/pylint-django/issues/43>`__ - Foreign
key ID access (``somefk_id``) does not raise an 'attribute not found'
warning
- `#31 <https://github.com/PyCQA/pylint-django/issues/31>`__ - Support
for custom model managers (thanks
`smirolo <https://github.com/smirolo>`__)
- `#48 <https://github.com/PyCQA/pylint-django/pull/48>`__ - Added
support for django-restframework (thanks
`mbertolacci <https://github.com/mbertolacci>`__)

Version 0.6
-----------

- Pylint 1.4 dropped support for Python 2.6, therefore a constraint is
added that pylint-django will only work with Python2.6 if pylint<=1.3
is installed
- `#40 <https://github.com/PyCQA/pylint-django/issues/40>`__ - pylint
1.4 warned about View and Model classes not having enough public
methods; this is suppressed
- `#37 <https://github.com/PyCQA/pylint-django/issues/37>`__ - fixed an
infinite loop when using astroid 1.3.3+
- `#36 <https://github.com/PyCQA/pylint-django/issues/36>`__ - no
longer warning about lack of ``__unicode__`` method on abstract model
classes
- `PR #34 <https://github.com/PyCQA/pylint-django/pull/34>`__ - prevent
warning about use of ``super()`` on ModelManager classes

Version 0.5.5
-------------

- `PR #27 <https://github.com/PyCQA/pylint-django/pull/27>`__ - better
``ForeignKey`` transforms, which now work when of the form
``othermodule.ModelClass``. This also fixes a problem where an
inferred type would be ``_Yes`` and pylint would fail
- `PR #28 <https://github.com/PyCQA/pylint-django/pull/28>`__ - better
knowledge of ``ManyToManyField`` classes

Version 0.5.4
-------------

- Improved resiliance to inference failure when Django types cannot be
inferred (which can happen if Django is not on the system path

Version 0.5.3
-------------

- `Issue #25 <https://github.com/PyCQA/pylint-django/issues/25>`__
Fixing cases where a module defines ``get`` as a method

Version 0.5.2
-------------

- Fixed a problem where type inference could get into an infinite loop

Version 0.5.1
-------------

- Removed usage of a Django object, as importing it caused Django to
try to configure itself and thus throw an ImproperlyConfigured
exception.

Version 0.5
-----------

- `Issue #7 <https://github.com/PyCQA/pylint-django/issues/7>`__
Improved handling of Django model fields
- `Issue #10 <https://github.com/PyCQA/pylint-django/issues/10>`__ No
warning about missing **unicode** if the Django python3/2
compatability tools are used
- `Issue #11 <https://github.com/PyCQA/pylint-django/issues/11>`__
Improved handling of Django form fields
- `Issue #12 <https://github.com/PyCQA/pylint-django/issues/12>`__
Improved handling of Django ImageField and FileField objects
- `Issue #14 <https://github.com/PyCQA/pylint-django/issues/14>`__
Models which do not define **unicode** but whose parents do now have
a new error (W5103) instead of incorrectly warning about no
**unicode** being present.
- `Issue #21 <https://github.com/PyCQA/pylint-django/issues/21>`__
``ForeignKey`` and ``OneToOneField`` fields on models are replaced
with instance of the type they refer to in the AST, which allows
pylint to generate correct warnings about attributes they may or may
not have.

Version 0.3
-----------

- Python3 is now supported
- ``__unicode__`` warning on models does not appear in Python3

Version 0.2
-----------

- Pylint now recognises ``BaseForm`` as an ancestor of ``Form`` and
subclasses
- Improved ``Form`` support
- `Issue #2 <https://github.com/PyCQA/pylint-django/issues/2>`__ - a
subclass of a ``Model`` or ``Form`` also has warnings about a
``Meta`` class suppressed.
- `Issue #3 <https://github.com/PyCQA/pylint-django/issues/3>`__ -
``Form`` and ``ModelForm`` subclasses no longer warn about ``Meta``
classes.