Updating Django from 1.x to 2.x

Updating the software application to latest releases is very important. Because latest releases always includes new features which boosts development process and resolves potential problems.

Why to update to from Django 1.x to 2.x ?

• Django 1.0 is first stable version so, it obvious that it contains less features.
• Django 1.1 ORM improvements
  • Aggregate support
    • It includes RDBMS agregate features COUNT(), MAX(), MIN(), etc
  • Query expressions(i.e F object)
    • F object is a new feature in ORM queries. By using F queries we can refer to another field on the query and can traverse relationships to refer to fields on related models.
  • Model Improvements
    • Added managed option in django model Meta class. if managed=True then ORM can make database changes like dropping, creating and updating the table structure/data.
    • Default value of managed is True
• Django 1.2 new features
  • Support for multiple database connections in a single Django instance.
  • Model validation before saving the data into the database(i.e data type, uniqueness of database table record, etc)
  • Improved protection against CSRF attacks.
• Django 1.3 new features
  • Built-in support for writing class-based views using generic views.
  • Built-in support for python logging.
  • In previous versions of django it was common to place static assets in MEDIA_ROOT along with user-uploaded files, and serve them both at MEDIA_URL.
  • Static assets should now go in static/ subdirectories of our apps or in other static assets directories listed in STATICFILES_DIRS, and will be served at STATIC_URL.
• Django 1.4 features & deprecations
  • Django 1.4 has dropped support for Python 2.4. Python 2.5 is the minimum required Python version.
  • The Biggest feature added in this version is support for timezones. Based on the timezones datetime/date objects will be handled.
  • It supports integration with in-browser testing frameworks like Selenium.
  • django.test.LiveServerTestCase base class allows us to test the interactions with front-end and back-end.
  • ORM improvements includes bulk_create and prefetch_related(i.e batch-load related objects).
• Django 1.5 features
  • This release blasted with new feature Configurable User model where we can use our own user model.
  • It’s also the first release that supports Python3.
  • GeoDjango now supports PostGIS 2.0.
  • It provides better support for streaming responses with class django.http.StreamingHttpResponse.
• Django 1.6 features
  • It supports persistent database connections. This avoids the overhead of re-establishing a connection at the beginning of each request.
  • Database transaction management improved. Database-level autocommit is now turned on by default. This makes transaction handling more explicit and should improve performance.
  • It introduced a new test runner suit that allows more flexibility in the location of tests(i.e django.test.runner.DiscoverRunner). With test discovery, tests can be located in any module whose name matches the pattern test*.py.
  • A new django.db.models.BinaryField model field allows storage of raw binary data in the database.
• Django 1.7 features & deprecations
  • syncdb management command replaced with migrate
  • django.db.models.signals.pre_syncdb and django.db.models.signals.post_syncdb have been deprecated and replaced by pre_migrate and post_migrate respectively.
  • django.utils.simplejson is removed and we can use python’s json module(i.e import json).
  • HttpResponse, SimpleTemplateResponse, TemplateResponse, render_to_response(), index(), and sitemap() no longer take a mimetype argument. It’s been renamed to content_type.
• Django 1.8 features
  • It now supports multiple template engines like Jinja2, django, Mako, etc.
  • django-secure third-party library had been integrated into Django to improve the security.
  • PostgreSQL specific functionality like ArrayField, HStoreField, IntegerRangeField, BigIntegerRangeField, etc. fields support added.
  • Added ORM support for Query Expressions, Conditional Expressions, and Database Functions.
  • Improved the unittest functionality.
• Django 1.9 features & deprecations
  • AUTH_PASSWORD_VALIDATORS setting added to help prevent the usage of weak passwords by users.
  • Permission mixins support added for generic class based views.
  • Implicit QuerySet __in lookup removed (i.e Model.objects.filter(related_id__in=RelatedModel.objects.all()))
  • Dropped support for PostgreSQL 9.0, Oracle 11.1
• Django 1.10 features
  • Enabled full text search for PostgreSQL database table columns
  • The User model in django.contrib.auth originally only accepted ASCII letters and numbers in usernames.
• Django 1.11 features & deprecations
  • The Django 1.11.x series is the last to support Python 2. The next major release, Django 2.0, will only support Python 3.4+
  • Database table indexes available in model meta class (i.e Meta.indexes).
  • Template-based widget rendering support added.
  • Added support for Subquery expressions

    posts = Post.objects.filter(published_at__gte=one_day_ago)
    Comment.objects.filter(post__in=Subquery(posts.values('pk')))
    

  • Dropped support for PostgreSQL 9.2 and PostGIS 2.0
• Django 2.0 features & deprecations
  • It only support’s Python3.4+. It dropped support for Python<3.
  • It simplified the url routing syntax by introducing the path converters.
  • Responsive user interface feature for django admin.

Check list to update projects from Django1.x to Django2.x?

• Check-out the version of the django on which the project is running.
• It’s recommended to update the current version to it’s next version (i.e django 1.x to django 1.x+1).
• Before updating the django version first we have to read it’s release notes for what are the features deprecated and what are the features introduced.
• Find replacements for deprecated features.
• In most django projects we use many third party packages. So, we have to take care of them too.
• If any third party package is deprecated then first we have to check for alternatives to it. If any alternative is available then use it.
• If no alternative found then update the existing package and use it.
• Remove all unused third party packages.
• After satisfying the requirements(i.e system softwares and pip packages) run the tests.
• If any failures while running tests then fix them.
• Try to remove all unused code(i.e you can use test coverage)
• Try to optimize the existing code by replacing it with new features wherever it’s required to speedup the application.
• Try to optimize the existing ORM queries with new features of ORM to speedup the query execution.
• Try to use path and path converters to make urls more readable.

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