Trying to extract individual bands from a multiband raster file.

Hi,
I have a bunch of rasters that contain multiple bands. I only want to use a few of the bands from these rasters, but I'm having a hard time extracting them automatically in Python. The only solution I've read online is to use the composite bands tool, but I don't understand how to set up the syntax to extract a single band from a raster; the tool help just states that it can be done but doesn't really explain how. Any advice?

Thanks,
-Scott