What exactly is None

[Griz]

In the documentation, it has

None is None, produces the result True

None not is None, produces the result True  <= is this wrong ... should it be None not is None, produces the result False instead of True.

What exactly is None?  Is it a space " " or "" or Null?

When I want to filter, should I use "==" or "Is" or does it make a difference?

Edited December 11, 2023 by Griz
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[Sara]

Hello Griz! 

Thank you for your feedback on documentation, None not is None produces False, there is a typo in it.

The None value is meant to be an empty cell. 

The 'is' and the '==' operators have different functions in formulas:

• 'is' means equals to: this operator can be used with any attribute type, and it only returns a binary True/False value.
• == means equals in comparison: it is inserted automatically between the left and right side of the formula. When it is used with nominal attributes containing a None (empty) value, it returns a binary true or false as well

While if you are talking about the filtering options in the Data Manager's query panel, consider that the difference between ==, != and is, not is is meaningless if both the compared attributes are nominal or binary due to the None operator properties used in Rulex Platform.

I hope this helps!