Creating subfolders in ArcPy's 'in_memory'

Question

Is there a way to create a subfolder in memory in ArcPy?

For example, instead of temporarily saving a dataset under:

r'in_memory/bufferOne'

I would like to save it under:

r'in_memory/buffers/bufferOne'

This spits out an error message, of course. But is there a way to still achieve the same effect?

Background: I am working on a tool that create a lot of intermediate data that does not need to be saved. Right now I am saving each intermediate output into separate folders, which makes it easier to check out the outputs during testing, and it avoids the annoyance of filtering when using things like arcpy.ListFeatureClasses() (that is actually the number one reason for using all these subfolders):

Now that I know that I am getting the correct results I would like to save most of these steps in_memory, to speed up the tool. It would be ideal if I could just adopt this structure and change a few paths in my script instead of adding a lot of filter logic.

Answer 1

No - in_memory workspaces are only similar to and not identical to geodatabase workspaces. They support feature classes but not feature datasets.

This is documented on the Using in-memory workspace help page:

Feature datasets or folders cannot be created in the in-memory workspace.