Need help building my first script

AntoineCantin

Hi, I'm trying to build a script, my first, so that it would create another version of some polygons in a shapefile (per example zoning)by erasing some polygons contained in a different shapefile (called hydro). I don't have a Pro license, so I use the "Union then delete" method instead of the erase tool. I don't want the attributes from the hydro table. I want to duplicate the script to apply those modification to other shapefiles. So here is what I found for the moment:

# Import the system modules

import arcpy

from arcpy import env

# Set the current workspace

# (to avoid having to specify the full path to the feature classes each time)

env.workspace = "c:/data/data.gdb"

# For first layer

  #Turn off all fields of hydro.shp so when union is done, the attributes table will only keep the fields from "zoning", leaving out the turned off fields of "hydro"

  #Can't find script lines for that

  #union layerName with hydro.shp

  #Source:  http://help.arcgis.com/En/Arcgisdesktop/10.0/Help/index.html#//00080000000s000000

  arcpy.Union_analysis (["layerName", "hydro", "layerName_union", "ALL")

  #select FID_hydro <> -1

  #Source: http://help.arcgis.com/En/Arcgisdesktop/10.0/Help/index.html#//001700000071000000)

  arcpy.SelectLayerByAttribute_management ("layerName_union", "NEW_SELECTION", " [FID_hydro] <> '-1' ")

  #If selection > 0, delete FID_hydro <> -1

  #Source:  http://help.arcgis.com/EN/ARCGISDESKTOP/10.0/HELP/index.html#//001700000036000000

  if int(arcpy.GetCount_management(layerName_union).getOutput(0)) > 0:

       arcpy.DeleteFeatures_management(layerName_union)

  #export data layerName_union as shapefile

  #Source:  http://resources.arcgis.com/en/help/main/10.1/index.html#//001200000020000000

  arcpy.FeatureClassToFeatureClass_conversion("layerName_union","C:/Chemin/vers/dossier","layerName_noHydro.shp")

# Repeat for other layers

Anyone know how to use script to turn off all the field of a layer?

Would those steps work? Is there something missing?

Thanks,

AntoineCantin

import arcpy
import os


#delete any data tha might be stored in memory
arcpy.Delete_management("in_memory")


#set workspace to where all your shapefiles are
arcpy.env.workspace="C:/Users/Antoine/Desktop/MRCL - Local/Ketar_shp"


#define where the hydro shapefile is located, ideally in a different folder than the others
hydroshp="C:/Users/Antoine/Desktop/MRCL - Local/Ketar_shp/hydro/hydro.shp"


fcs=arcpy.ListFeatureClasses()
for fc in fcs:
    #create an empty list to be populated with the original shapefile's field names
    fieldnames=[]


    #List all fields in the shapefile and populate the fieldnames list with their names
    fields=arcpy.ListFields(fc)
    for field in fields:
        fieldnames.append(field.name)


    #define layer name for each shapefile
    fclayer=fc.rstrip(".shp")


    #create output files for the clip and the union layers
    fcClip=os.path.join("in_memory",fclayer+"clip")
    fcUnion=fclayer+"union.shp"#os.path.join("in_memory",fclayer+"union")


    #clip the shapefile using the hydro layer
    arcpy.Clip_analysis(fc,hydroshp,fcClip)


    #create a union of the clipped hydro and the shapefile
    arcpy.Union_analysis([fc,fcClip],fcUnion,"ALL")


    #delete any unnecessary fields from your union shapefile
    unionfields=arcpy.ListFields(fcUnion)
    for ufield in unionfields:
        if ufield.name not in fieldnames:
            arcpy.DeleteField_management(fcUnion,ufield.name)


    #Create layer file so you can perform a selection on it
    arcpy.MakeFeatureLayer_management(fcUnion,fclayer+"_sansO")
    arcpy.SelectLayerByLocation_management(fclayer+"_sansO","WITHIN",fcClip)


    #If selection > 0, delete features
    if int(arcpy.GetCount_management(fclayer+"_sansO").getOutput(0)) > 0:
        arcpy.DeleteFeatures_management(fclayer+"_sansO")


    #export data layerName_union as shapefile (works)
    arcpy.FeatureClassToFeatureClass_conversion(fclayer+"_sansO","C:/Users/Antoine/Desktop/MRCL - Local/Ketar_shp/shapes_sansO.gdb",fclayer+"_sansO")


print "done!!"

Someone helped me, here's what we have come up with!