Django model field: Checking "if field is not None" vs. "if field"
83392
Why is "if not someobj:" better than "if someobj == None:" in Python?
54829
How do I filter ForeignKey choices in a Django ModelForm?
23730
Why is 'True == not False' a syntax error in Python?
14264
What is better: multiple "if" statements or one "if" with multiple conditions?
39799
Does the `is` operator use a __magic__ method in Python?
17037
When are "if" and "whether" equivalent?
88724
OR condition in Views Contextual Filters
37752
What is the easiest way of telling whether a BNF grammar is ambiguous or not?
4286
How to set the default value of an exposed filter rather than -Any-?
151505
Django: Get an object form the DB, or 'None' if nothing matches
93761
"if", and "elif" chain versus a plain "if" chain
127655
How do I do a not equal in Django queryset filtering?
59676
How to assign currently logged in user as default value for a model field?
34821
"None is" or "none are"
42738
Using If Then Else statement in ArcMap ModelBuilder?
6454
Perform feature normalization before or within model validation?
107530
How to tell whether a field is required or not in Apex by describe fields