Batch Clipping in ArcGIS Desktop using ArcPy?

Question

I've come across a few similar questions for older versions of ArcGIS, but haven't found a suitable answer for ArcGIS 10.

I have two polygon shapefiles that cover a large area (e.g. an entire State/Province). The first shapefile represents land cover for the entire State and the second represents 50 individual watersheds. I would like to clip the land cover shapefile based on each watershed (each has a unique name stored in a field). I would then like to save the output clipped files (one for each of the 50 watersheds) using the watershed name.

Given that there are 50 clips to be performed this process is a great candidate for batch processing.

Answer 1

The following script clips polygon watersheds to polygon county boundaries, naming each output featureclass something like HspWBD_HU12_county name. Tested and it works. Make sure your values in the NAME field have no special characters or spaces (simple Python string methods can clean that up for you).

import arcpy

arcpy.env.workspace = r'D:\Projects\GDBs\slowbutter.gdb\IPAS'
rows = arcpy.SearchCursor('HspAOI')
for row in rows:
    feat = row.Shape
    arcpy.Clip_analysis('HspWBD_HU12', feat, 'HspWBD_HU12_' + str(row.getValue('NAME')), '')

Answer 2

As you use ArcGIS 10, i would use modelbuilder with builtin tool: Iteration Feature Selection to perform this task. See the pseudo-model in the picture. it does not need to know python scritping at all.

Answer 3

This sounds exactly like what the Split tool from the Analysis toolbox does.

However, it requires an ArcInfo license to run so is not available to the majority of ArcGIS Desktop users so I like Chad's answer which will work for ArcGIS 10 Desktop users with ArcView and ArcEditor level licenses too.

Answer 4

You can do this the way you want if you run another tool in batch mode first: Conversion Tools > To Geodatabase > Feature Class to Feature Class. That will let you use an expression to take your watershed layer and pull out each watershed invidividually and save it as its own feature class, then you'll have 50 individual layers you can use with the Clip tool in batch mode.

Answer 5

The Split tool in ArcGIS does exactly this.