signal.butter

from scipy import signal

b,a=signal.butter(4, 0.1*2) # stop bandの周波数が0.1である4次のbutter worth filterの係数を得る

from scipy import signal

b,a=signal.butter(4, 0.1*2) # Obtain filter coefficients for 4th order butter worth filter with stopband at the frequency of 0.1