Add sequential ids to a column using calculate field

Question

So I have a bunch of ObjectIDs that have null id values. These null values start from ObjectID 20866 to 21899. ObjectID 20865 has id value 30542 so the next id value for ObjectID 20866 would be 30543 and then so on till ObjectID 21899.

How can I do this using Python in Calculate Field using a For loop and may be a ++ counter?

I am using ArcGIS Pro 3.1.1.

• evv_gis: Just select the null rows, then use field calculator and make the expression: !objectid! + 9677.
• Arthur_Morgan: Nice thanks for the super quick response, so what's 9677 doing?
• evv_gis: It's the difference between 30542 and 20865.
• Arthur_Morgan: Wait don't you think instead of !objectid! it should be !id! since the first calculated id value will be 1 + 30542 where 30542 is the last id value before the null id values start?
• evv_gis: No. You should use field calculator on the ID field. The expression will be ID = !objectid! + 9677.

Answer 1

Select the rows where ID is null, then you can use the field calculator on the ID field with the expression !objectid! + 9677 since 9677 is the difference in value of your OBJECTID and ID fields.