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     Antipatterns

    1. A GET request with side-effects
    2. A model with a …Model suffix
    3. Chaining querysets together
    4. Checking ownership through the UserPassesTestMixin
    5. Checking request method with if request.POST
    6. Constructing a new form when validation fails
    7. Fetching the logged in user with a query
    8. Filter on arbitrary input like request.GET
    9. Filtering in the template
    10. Foreign key with _id suffix
    11. Giving related_name=… the same name as the relation
    12. Manually constructing a slug
    13. Modifying slugs and primary keys of model objects
    14. (Over)use of .values()
    15. Passing parameters directly in the query string of a URL
    16. Plural model class names
    17. Refer to the User model directly
    18. Rendering content after a successful POST request
    19. Rendering into JavaScript
    20. Return a JsonResponse with safe=False
    21. Signals
    22. Use datetime.now as default=… for a created_on field
    23. Use .get(…) to retrieve the object in a view
    24. Using a FloatField for currencies
    25. Using commit=False when altering the instance in a ModelForm
    26. Using len(…) on a QuerySet with no further use
    27. Using multiple forms on the same page without prefixing
    28. Using regular HTML comments instead of Django template comments
    29. Using request.POST or None

     Patterns

    1. A SET(…) delete handler with the object as parameter
    2. Annotate a condition as BooleanField
    3. Date(Time)Fields that store a week or month
    4. Match multiple strings in a case-insensitive manner
    5. Set values to a created/updated object in a class-based view

     Difference between …

    1. ForeignKey and OneToOneField
    2. reverse and redirect

     Troubleshooting

    1. A certain field does not appear in the migrations and in the database table
    2. Can not extract/filter a Date(Time)Field when time zones are enabled