My understanding is that there is not. Only a subset of what is available using ArcObjects is exposed via ArcPy. Another input parameter that is on many system tool dialogs but not accessible to Python Toolbox and Python Script tools is the color picker.
As commented by @Vince:
Never, ever use the Polygon constructor without a SpatialReference
(spatial_reference is the second parameter). But your problem is
failure to create new Point objects, so the Array just has one
repeating vertex. The code samples provide the template, and they
create new Point objects for each loop iteration (it's best ...
This solution works using the Attribute Editor, but does not work through the Attribute Table.
Select the records you want to update to NULL
Open the Attribute Editor from the Editor toolbar
If you have more than one feature you want to update, select the top row (this makes any attributes you edit update all selected records)
In the field you want to ...
You could replace any empty strings with another string from the field calculator.
Using python, where STATE_NAME is the field:
If you mean Null not as a string you could try using a codeblock:
if x =="":
Under field, replace(!STATE_NAME!)
To do this I think you would need to solve a number of problems.
I think that the first of these would be to record, perhaps as a feature class of rectangular polygons, each extent visited by your users.
This would mean having each extent change trigger the capture of that extent polygon.
Then you would also need to capture the time each extent was on ...