Trying to modify records from one shapefile to another gives Error 999999?

Question

I am trying to update the atrribute data of a feature class with respect to another one by matching a common field. But it is returning an error for the setValue command. My code looks like:

import arcpy
fc="D:/Geonames_CA.gdb/Export_Output"
fs="D:/abc.gdb/Export"
rows = arcpy.SearchCursor(fc) 
fldList=arcpy.ListFields(fc)
rws = arcpy.SearchCursor(fs)
flList=arcpy.ListFields(fs)
for row in rows:
    for fld in fldList:
        a = row.getValue("PLACE_NAME")
        a_xmin=row.getValue("XMIN")
        a_xmax=row.getValue("XMAX")
        a_ymin=row.getValue("YMIN")
        a_ymax=row.getValue("YMAX")
for rw in rws:
    for fl in flList:
        b = row.getValue("PLACE_NAME")
        b_xmin=row.getValue("XMIN")
        b_xmax=row.getValue("XMAX")
        b_ymin=row.getValue("YMIN")
        b_ymax=row.getValue("YMAX")
        if b==a:
            cursor = arcpy.UpdateCursor(fs)
            for r in cursor:
                r.setValue(b_xmin, a_xmin)
                r.setValue(b_xmax, a_xmax)
                r.setValue(b_ymin, a_ymin)
                r.setValue(b_ymax, a_ymax)
                cursor.updateRow(r)
            del r, cursor

I am only getting this error:

Traceback (most recent call last): File "C:\Python27\ArcGIS10.1\Lib\site-packages\pythonwin\pywin\framework\scriptutils.py", line 326, in RunScript exec codeObject in main.dict File "D:\Script2.py", line 25, in r.setValue(b_xmin, a_xmin) File "C:\Program Files\ArcGIS\Desktop10.1\arcpy\arcpy\arcobjects\arcobjects.py", line 1007, in setValue return convertArcObjectToPythonObject(self._arc_object.SetValue(*gp_fixargs(args))) RuntimeError: ERROR 999999: Error executing function.

Answer 1

Your code looks to do a lot of unnecessary things. For instance, you iterate over filed list, but never use variables fl or fld. So here is code that could do what you need from my understanding.

It first gather all the place_name variables and put it in a dictionary and after, iterate thought the second feature class and update the values.

import arcpy
fc="D:/Geonames_CA.gdb/Export_Output"
fs="D:/abc.gdb/Export"

#Reading values
rows = arcpy.SearchCursor(fc) 
dictValues={}
for row in rows:
    a = row.getValue("PLACE_NAME")
    a_xmin=row.getValue("XMIN")
    a_xmax=row.getValue("XMAX")
    a_ymin=row.getValue("YMIN")
    a_ymax=row.getValue("YMAX")
    if not dictValues.has_key(a):
        dictValues[a]=(a_xmin,a_xmax,a_ymin,a_ymax)
    else:
        #Log error!
        arcpy.AddWarning("Duplicate PLACE_NAME in input: " + a )
del row, rows

#Writing values
cursor = arcpy.UpdateCursor(fs)
for r in cursor:
    b=r.getValue("PLACE_NAME")
    if dictValues.has_key(b):
        r.setValue("XMIN", dictValues[b][0])
        r.setValue("XMAX", dictValues[b][1])
        r.setValue("YMIN", dictValues[b][2])
        r.setValue("YMAX", dictValues[b][3])
        cursor.updateRow(r)
    else:
        #Log error!
        arcpy.AddWarning("No PLACE_NAME " + b + " in input" )
del r,cursor
del dictValues

Hopes this helps you figure out your problem and understand more how arcpy and python works.