arcgis desktop - Adding new field in ArcMap from data of existing field?

I want to create a new field with years data.

There is an existing field with the timestamp YYYYMMDDHHMM but I just want the years from that field to the new field.

That way I can display just the years when I create a graph.

Is there anyone that can explain the code to do this?

I am not a programmer.

Answer

Assuming your existing timestamp field is a string:

1. 
   

   Add a new field (Open the attribute table of your feature class>Click Upper Left Dropdown>Add Field) as a long integer.

   
   



2. 
   

   Right click new field and select "Calculate Field".

   
   


3. 
   

   Change your parser to Python and use the following expression:

   
   

   !ExistingTimeStampField![:4]

   
   

Note that you need to replace the "ExistingTimeStampField" between the exclamations with the actual name of your field (should be able to auto-populate in the Fields list box). This will trim off the leading 4 characters from your existing field which I presume will always be the 4-digit year.

Edit: If you wish to break out more information you can simply update the indices of your query like such (Note that my original [:4] is the same as saying [0:4]):

!ExistingTimeStampField![4:6]

This would return the MM in YYYYMMDDHHMMSS. [6:8] would return the DD, and so on. See here for a more detailed explanation of substrings: http://docs.python.org/tutorial/introduction.html#strings