can't set up script tool parameters

Question

I'm using arcgis 10.0. I red the ESRI doc to setting up script tools parameters, but I don't succeed at setting them up.

My parameters before (without variable)

#arcpy.env.workspace = r'Z:\Documents\SIG\tests\synthese_tocorrect.gdb'
#pochoir = r'Z:\Documents\SIG\tests\decoupe.shp' #the clip layer with multiple polygons
#outFolder = r'Z:\Documents\SIG\tests\sorties'

My parameters after, with issues :

import arcpy, os
from arcpy import env
inWorkspace = arcpy.GetParamterAsText(0)#Refers to the geodatabase
pochoir = arcpy.GetParamterAsText(1) #Refers to the existing clip layer
outFolder = arcpy.GetParamterAsText(2) #Output folder.
env.workspace = inWorkspace
arcpy.MakeFeatureLayer_management(pochoir, "pochoirlyr") #Create layer to allow for selection
fcList = arcpy.ListFeatureClasses() #the feature class to be clipped by each of the polygon of the clip layer
OIDField = arcpy.Describe("pochoirlyr").OIDFieldName #Get name of OID field

for fc in fcList:
    arcpy.MakeFeatureLayer_management(os.path.join(arcpy.env.workspace, fc), "lyr")
    pocursor = arcpy.SearchCursor("pochoirlyr")
    for porow in pocursor:
        sql = '"' + OIDField + '" = ' + str(porow.getValue(OIDField)) #SQL to select one feature
        arcpy.SelectLayerByAttribute_management("pochoirlyr", "", sql) #Select polygon feature by OID
        arcpy.SelectLayerByLocation_management("lyr","INTERSECT","pochoirlyr") #Select feature layer to be clipped by selected clip feature 
        if arcpy.Describe("lyr").FIDSet: #Check for selection
            out_poly = os.path.join(outFolder, fc + "_" + str(porow.getValue(OIDField))) #Output feature class
            arcpy.Clip_analysis(fc, "pochoirlyr", out_poly)
    del porow
    del pocursor
    arcpy.SelectLayerByAttribute_management("pochoirlyr", "CLEAR_SELECTION")
    arcpy.Delete_management("lyr")

And in the properties of the script tools :

• geodatabase : Workspace or Feature Dataset, input, no multivalue...
• pochoir : shapefile, input, no multivalue...
• sorties : Folder, output...

But when I choose a different parameter when opening the script tool GUI, it does not work. It does the job with the IDE parameters.

Any help ?

Answer 1

You need to use the

arcpy.GetParameterAsText(0)

method:

See examples from:

Understanding script tool parameters

Answer 2

I use sys.argv[n] but GetParameterAsText is the same thing, but be aware that argv[0] is the script, argv[1] is the first parameter as opposed to GetParameterAsText(0) being the first parameter.

On each iteration (after the clip) you need to clear the selection or remake the layers "lyr" and "pochoirlyr" otherwise it will only work on the first iteration then both layers will be empty after that, layer selection is funny like that.

I think this will do what you're after:

import arcpy, os, sys
from arcpy import env

inWorkspace = sys.argv[1]#Refers to the geodatabase
pochoir = sys.argv[2] #Refers to the existing clip layer
outFolder = sys.argv[3] #Output folder.
env.workspace = inWorkspace
fcList = arcpy.ListFeatureClasses() #the feature class to be clipped by each of the polygon of the clip layer
OIDField = arcpy.Describe(pochoir).OIDFieldName #Get name of OID field from the feature class

for fc in fcList:
    pocursor = arcpy.SearchCursor(pochoir) # cursor from the feature class
    for porow in pocursor:
        sql = '"' + OIDField + '" = ' + str(porow.getValue(OIDField)) #SQL to select one feature
        arcpy.MakeFeatureLayer_management(pochoir, "pochoirlyr",sql)  #Create layer with selection already
        arcpy.MakeFeatureLayer_management(os.path.join(arcpy.env.workspace, fc), "lyr")
        arcpy.SelectLayerByLocation_management("lyr","INTERSECT","pochoirlyr") #Select feature layer to be clipped by selected clip feature

        if arcpy.Describe("lyr").fidSet: #Check for selection in the lyr
            out_poly = os.path.join(outFolder, fc + "_" + str(porow.getValue(OIDField))) #Output
            if arcpy.Exists(out_poly) or arcpy.Exists(out_poly + ".shp"):# check it doesn't already exist'
                arcpy.AddWarning("Sorry, that feature class already exists")
            else:
                arcpy.Clip_analysis(fc, "pochoirlyr", out_poly)

         # delete the layers so you can use the names again
         arcpy.Delete_management("lyr")
         arcpy.Delete_management("pochoirlyr")

    del porow
    del pocursor

Instead of making the layer then selecting by attributes against it I have modified it so that it creates the layer "pochoirlyr" using the SQL as the whereclause. On each iteration the "lyr" and "pochoirlyr" are created and delteted which avoids confusion about what's in the layer/not in the layer, what's selected and what isn't.. a clean start every time.