Hello, new tops user here.

I have a Solaris network that contains multiple USD render ROPs, I would like to build a TOP network that will:

• Render each rop sequentially.
  
• Convert the .exr files from each ROP to .png in the same location of each .exr with the same filename, just replacing

  *.exr
  

  with

  *.png
  

Currently in my TOP network I am using RopFetch nodes followed by imagemagic nodes set to python expression language and operation "convert" with the "output file path" set to:

I would expect this to use python string slicing to strip .exr from the incoming file path and replace it with .png for output, however I get my output files named:
Is this just bad syntax on my part? I would really like to set the file paths procedurally like this and avoid a spider web of relative reference parameters from the USD render ROPs to build the output file names.

The rats nest of hscript vs python vs backticks vs tops attribs can be tricky.

Lately myself and coworkers steer away from @pdg_input, and instead generate standalone new attributes using the string filtering and attrib create top nodes to define them. It's more nodes, but we find it a little easier to debug.

Attached an example.

OK got that working, thanks Matt!