topic Re: da.walk can't get featureclasses in featuredataset? in Python Questions

da.walk can't get featureclasses in featuredataset?

pyfans — Wed, 30 Aug 2023 09:32:46 GMT

Can arcpy.da.Walk() function find featureclasses within a featuredataset in gdb? For example, there are a featuredataset 'DT' and a featureclass 'A' in gdb, and a featureclass 'B' in 'DT', after walk(gdb), it can only find DT and A, but no B. Is it normal ?

I use 10.8.2.

Re: da.walk can't get featureclasses in featuredataset?

AlfredBaldenweck — Wed, 30 Aug 2023 12:32:09 GMT

Each feature dataset is considered its own environment by arcpy, so functions like Walk() and ListFeatureClasses() will ignore stuff in a feature dataset if run on a geodatabase.

What you have to do instead is iterate through what's returned by Walk, check if it's a featuredataset, then change the environment to the featuredataset and list those feature classes in it.

Here's some sample code I wrote. In this case, "fd" was originally the output of arcpy.ListFeatureDatasets(), but you could sub in the files from Walk()

dirP = #whatever gdb you were running Walk() on desc= (arcpy.da.Describe(fd)) if 'datasetType' in desc: if desc['datasetType'] == "FeatureDataset": arcpy.env.workspace = os.path.join(dirP, fd) fdFCList = arcpy.ListFeatureClasses() if fdFCList: for fc in fdFCList: fList.append([os.path.join( desc['catalogPath'],fc)]) # Reset the workspace or else this breaks. arcpy.env.workspace = dirP

Re: da.walk can't get featureclasses in featuredataset?

Luke_Pinner — Wed, 30 Aug 2023 21:45:32 GMT

Works for me in ArcMap 10.8.2. Given a FGDB with 2 FCs, "A" and "B" with "B" in feature dataset "FD":

import arcpy for parent, workspaces, datasets in arcpy.da.Walk("Default.gdb"): print("parent: %s"%parent) print("workspaces: %s"%workspaces) print("datasets: %s"%datasets)

Output showing that "B" is listed correctly in the feature dataset "FD":

parent: Default.gdb workspaces: [u'FD'] datasets: [u'A'] parent: Default.gdb\FD workspaces: [] datasets: [u'B']

Re: da.walk can't get featureclasses in featuredataset?

Luke_Pinner — Wed, 30 Aug 2023 21:52:07 GMT

@AlfredBaldenweck wrote:
Each feature dataset is considered its own environment by arcpy, so functions like Walk() and ListFeatureClasses() will ignore stuff in a feature dataset if run on a geodatabase.

Not quite right for Walk. You just need to keep iterating through the Walk results. Any feature datasets are considered workspaces, so Walk will recurse to them and return their contents.

Re: da.walk can't get featureclasses in featuredataset?

pyfans — Thu, 31 Aug 2023 01:11:11 GMT

Yes, after try again, I find it works when there are no any non-english (or say non-ascii?) character in gdb, but if there are Chinese character in gdb or featuredataset or featureclass's name, it just can't get featureclasses in featuredataset.

I tried 10.8.2 and 10.4.1.

Re: da.walk can't get featureclasses in featuredataset?

Luke_Pinner — Thu, 31 Aug 2023 04:24:09 GMT

I think feature class names need to use ascii characters only. From the help:

Re: da.walk can't get featureclasses in featuredataset?

AlfredBaldenweck — Thu, 31 Aug 2023 13:09:36 GMT

Good to know, thanks for the clarification.

I avoid Walk because it doesn't do quite what I want it to do.