Essentially I am trying to get xy coordinates from a CSV. I have already converted the CSV to DBase and added 2 new double fields for LAT and LONG. But the original latitude and longitude values are in string type fields and contain "NA" values for some of the coordinates. I can remove the NA fields using a cursor because they are useless for plotting xy coordinates but I still am unable to copy the coordinate data from the string type columns to the new double type columns.

I have also tried the 2 following cursors as well

and regardless of what I do I receive the following error:
ExecuteError: ERROR 999999: Error executing function.
The value type is incompatible with the field type. [LAT]