this is the Python code

def lowpass (Data, period):
a=2.0/(1+period)
out=[]
for i in range(2, len(Data)):
if i==2:
LP=np.array([Data[0] for _ in range(3)])
print (LP)

LP[0]=(a-0.25*a*a)*Data[i-2] + 0.5*a*a*Data[i-1] - (a-0.75*a*a)*Data[i] + 2*(1.-a)*LP[1] - (1.-a)*(1.-a)*LP[2]
out.append (LP[0])
LP=np.roll(LP, 1)
return out