The ObjectID_1 field most commonly happens when you import a feature class that already has an ObjectID field into a geodatabase, which tries to create its own OID field but since the default name is already taken, it names it with _1.
Because of the mismatched field names, you would need to create a field mappings object, which is a bit annoying for just one off-named field. You could recreate the feature class with only the one default named OID field so Append would work without field mappings, or use the cursors as you were attempting to do.
Here's what I would do for cursors
dsc = arcpy.Describe(Source)
target_field_Names = [f.name for f in arcpy.ListFields(Source)]
source_field_Names = [
f.name for f in arcpy.ListFields(Source)
if f.type != "OID"
and f.name in target_field_Names
]
with arcpy.da.SearchCursor(Source,fieldnames) as sCur:
with arcpy.da.InsertCursor(Target,lstFields) as iCur:
for row in sCur:
iCur.insertRow(row)
And here's what I would do for using append with field mappings. I created a fuzzy_fieldmap() function that will create field mappings only with fields that exist in both the source and target tables (excluding ObjectID fields).
import arcpy
def main():
fieldmappings = fuzzy_fieldmap(sourceTable, targetTable)
arcpy.Append_management(
sourceTable,
targetTable,
"NO_TEST",
fieldmappings
)
print(arcpy.GetMessages())
def fuzzy_fieldmap(input_table, target_table):
input_fields = [
f.name.upper() for f in arcpy.ListFields(input_table)
if f.type != "OID" or f.name != "OBJECTID"
]
target_fields = [
f.name.upper() for f in arcpy.ListFields(target_table)
if f.type != "OID" or f.name != "OBJECTID"
]
# Main FieldMapings object to hold FieldMap objects
fms = arcpy.FieldMappings()
# dictionary for FieldMap objects
fm_vars = {}
for t_field in target_fields:
if t_field in input_fields:
# Create the FieldMap object
fm_vars[t_field] = arcpy.FieldMap()
# Add fields to FieldMap object
# Add target field first so the output gets those field properties
fm_vars[t_field].addInputField(target_table, t_field)
fm_vars[t_field].addInputField(input_table, t_field)
# Add the FieldMap objects to the FieldMappings object
fms.addFieldMap(fm_vars[t_field])
# Optional debugging section to print field mappings
for out_field in fms.fields:
print("{} ({}): {}".format(out_field.name, out_field.aliasName, out_field.type))
return fms
if __name__ == '__main__':
main()
