Here is the HighPass2 filter code in Python if you want it

def HighPass2 (Data, CutoffPeriod=50):
a=(0.707*2*np.pi)/CutoffPeriod
alpha1 = 1+(np.sin(a)-1)/np.cos(a)
b=1-alpha1/2.
c=1-alpha1

out=np.ones (len(Data))*Data
HP=np.zeros(3)

for i in range (2, len(out)):
HP[0] = b*b*(Data[i]-2*Data[i-1]+Data[i-2])+2*c*HP[1]-c*c*HP[2]
out[i]=HP[0]
HP=np.roll (HP, 1)

return out

'''
Ehlers' Decycler, S&C 9/2015
'''
def Decycle(Data, Period=50):
out=Data-HighPass2(Data,Period)
return out