Dissolving shapefile python script not working, syntax help please

Question

I do not understand why this simple script won't work. I can get it to dissolve in model builder but not from a script that I run from inside the map document. My output results are 4 polygons, just like my input file. I only want one.

Any suggestions?

# Import arcpy module
import arcpy
from arcpy import env
# Local variables:
env.workspace="C:\\Test\\shapefiles"
infeatures = "Multipolys.shp"
outfeatures = "C:\\Test\\shapefiles\\Dissolve.shp"
# Process: Dissolve
arcpy.Dissolve_management(infeatures, outfeatures, "", "", "SINGLE_PART", "DISSOLVE_LINES")

correct syntax is:

arcpy.Dissolve_management(infeatures, outfeatures, "", "", "MULTI_PART", "DISSOLVE_LINES")

ArcGIS 10.1 advanced.

Answer 1

The syntax is

Dissolve_management (in_features, out_feature_class, {dissolve_field}, {statistics_fields}, {multi_part}, {unsplit_lines})

You need to specify the dissolve_field as the third parameter - here you've left it blank.

• user12059: I intentionally left it blank (it is optional) as I do not want to dissolved on a field. I want it one polygon. Dissolving it on a field will not do this. Coordinates are the same, ran repair. Might need to run in 'foreground'. How would I do this?
• user12059: Duh. Syntax is 'arcpy.Dissolve_management(infeatures, outfeatures, "", "", "MULTI_PART", "DISSOLVE_LINES")' Still need to figure out how to run in foreground though.