I use subprocess to turn any single file in > single file out script into a batch processor that takes folders as input and output. I am sort of new to programm

I use subprocess to turn any single file in > single file out script into a batch processor that takes folders as input and output. I am sort of new to programming and I felt like this was quite dirty, but I didn't have the bindings anyway so I didn't have a choice. What are the downsides and upsides of calling subprocess versus bindings?