ListFeatureClasses comes back empty

[TomGeo]

Dear all,

I have a problem that comes and go's. Currently is is again immanent and I wonder what's causing it.

Working with ArcGIS 10 and using straight the IDLE from Python...

>>> import arcpy
>>> from arcpy import env
>>> env.workspace = r"Path\\to\\database.gdb"
>>> lstFDS = arcpy.ListDatasets("*", "FEATURES") # returns list of three items - correct
>>> lstPOLY = arcpy.ListFeatureClasses("*", "POLYGON", lstFDS[2])
>>> lstPOLY
[]

The dataset requested is holding almost 200 feature classes, all of them loaded with polygons.
I see all of them in ArcCatalog, but not in Python!

Anybody an idea? I already had a took care of remaining objects and invoked the garbage collector by hand but nothing.

Cheers Thomas

[MarcinGasior]

Your script works ok.
Does your third dataset (Python index = 2) contain polygon feature classes?

Maybe try checking lstPOLY in this way:

for fc in lstPOLY:
    print fc

[TomGeo]

The print loop comes back empty as well...

The weird thing is that one day there are no problems with it and the other one I have the stuff going on that currently happens. I restarted the machine, took care of unused objects etc.
The script works and some time the machine has ha bad day and isn't cooperating. :confused:

It's installed on a Windows Server 2008 R2, has plenty of RAM and memory on the HDD...

However, I created a new File Geodatabase, created the Feature Datasests and copied all the Feature Classes into the new GDB... now it works!?!

Thomas