This demo shows off cocotb and pyfda.
Youtube video
cocotb lets you write your HDL simulations in Python, which is fantastic because it allows you to leverage Python's huge library support (one of the examples is connecting a simulation to your local network).
In this demo I use Python's standard wave library to read and write wave files. The test.py testbench sends the input wave data through a filter and writes the output to an output wave file
pyfda is a filter design and analysis tool. It has a nice graphical front end and you can write FIR filters to a verilog module. In this demo I design a high pass filter and export it to filter.v.