IIR filter design: second order zero and poles combined (0003Py)
Channel: Digital Signal Processing
Date: 2017-11-02

Now we combine the zeros and poles and create a 2nd order bandstop filter. This is a pure digital filter where we create a notch with infinite damping at the notch frequency which is virtually impossible in the analogue domain.
See also:
https://docs.scipy.org/doc/scipy-0.19.1/reference/generated/scipy.signal.iirnotch.html