Field Calculator messages from Python Script

MikeLouwrens

I have a python script that uses the Field Calculator arctoolbox tool to populate fields in a geodatabase from a SQL database table.  I runs on many feature classes and many fields.

Occasionally I get a pop-up message from the Field Calculator:

[ATTACH=CONFIG]16111[/ATTACH]

I don't know which feature class or field is causing this message, or why it's happening.  Is there a way to log these errors and suppress the pop-up? And is there a way to report which Feature Class and Field is causing it?

Is there a better way to do what I'm doing?  Would an update cursor be better?  I suspect an update cursor might take longer, but not sure...

Thanks,
Mike.

FieldCalc.png

ChristopherThompson

I've discovered the problem is mis-matched field types (which is another issue altogether - they should be all the same!)  My GIS field type is correct, the join DB field type is incorrect.
.... I'm not sure quite how to structure the code to do a conversion of the field value within the CalculateField tool.  The code in the else statement works.

A couple of things:  those expressions in your calc field statement are really cumbersome I think and make it easy to miss some sort of syntax error. Try creating the new value outside the calculate_field tool and then simply referencing that as a variable inside the tool.  Also, don't bother testing for a double value, since the GIS field is double and that is where the value is going to update, simply make the value you supply a double, regardless if it started out life as a string  - float(x) wont' have any impact on x if its already a double or a floating point value but makes your string play nice with double fields.

if you wrap this into an update cursor it I think it would be reasonably easy to accomplish without implementing the calc field tool with something like this:

rows = arcpy.UpdateCursor(your arguments go here)
for row in rows:
 new_value = float(row.DBfield)
 row.GISfield = new_value
 rows.updateRow(row)

or maybe

for row in rows:
 new_value = row.DBfield
 row.GISfield = float(new_value)
 rows.updateRow(row)

or even

for row in rows:
 row.GISfield = float(row.DBfield)
 rows.updateRow(row)

Also, without trying to point out the obvious too much, since the source (database) seems to be providing mixed data, and this is probably the incorrect condition for your business practices, it might be worth the effort to get the database 'fixed' so it supplies the right data in the right format.  I know how that can go though, hope that suggestion doesn't rub too much salt in wounds!