Python: how to set a different output folder

Question

I want to transform some vectors to rasters in my folder but I have difficulties setting the output folder. The following code only allows me to output to the original database. I hope to output all results to the same folder instead of in their original database.

import arcpy
import os
workspace = "D:\Jiawei default download"
feature_classes = []
walk = arcpy.da.Walk(workspace, datatype="FeatureClass", type="Polygon")
for dirpath, dirnames, filenames in walk:
 if "Subbasin" in filenames:
 filenames.remove('Subbasin')
 for filename in filenames:
 feature_classes.append(os.path.join(dirpath, filename))
print feature_classes
for item in feature_classes[98:]:
 inFeatures = item
 valField = "wtdepaprjunmin"
 outRaster = item+"_r"
 print "processing "+item
# Execute PolygonToRaster
 arcpy.PolygonToRaster_conversion(inFeatures, valField, outRaster) 

• BruceDoh: Remember to escape your backslashes. The workspace above should be workspace = "D:\\Jiawei default download"

Answer 1

You set a workspace, so any outputs from the script will default to that location unless you explicitly put them somewhere else. Create a folder for the outputs, then write your output rasters to that folder.

import arcpy
import os
workspace = "D:\Jiawei default download"
feature_classes = []
outputFolder = r'c:\outputfolder'
walk = arcpy.da.Walk(workspace, datatype="FeatureClass", type="Polygon")
for dirpath, dirnames, filenames in walk:
 if "Subbasin" in filenames:
 filenames.remove('Subbasin')
 for filename in filenames:
 feature_classes.append(os.path.join(dirpath, filename))
print feature_classes
for item in feature_classes[98:]:
 inFeatures = item
 valField = "wtdepaprjunmin"
 outRaster = outputFolder+item+"_r"
 print "processing "+item
# Execute PolygonToRaster
 arcpy.PolygonToRaster_conversion(inFeatures, valField, outRaster) 

• April: Thanks! Seems easy enough but it gave me error message "ExecuteError: ERROR 999999: Error executing function." Trying to figure out
• mr.adam: Print your outRaster variable... I think you'll find it to be an invalid path. Using os.path.join() like you did earlier is really the best way to construct paths.
• April: Then what should I do to change output location?
• mr.adam: Well, because item looks like it'll be a full path to a feature class (not sure if it's in a gdb or if it's a shapefile), you need to pull just the basename of it, and then you need to decide what format you want the raster to be in. Because your out folder is not a geodatabase, I'd recommend creating tiffs. So: outRaster = os.path.join(outputFolder,os.path.splitext(os.path.basename(item))[0]+".tif") would probably do it. But, start by printing the variable, then read up on os.path.basename and os.path.splitext... that's where I'd recommend starting at least.