Q: TypeError risen when generating a TransferFunction with coefficients from SymPy #733

import control
import sympy as sym

# the "Control style"
n=list([[ [-9.762e-24, -2.283e-13, -0.0005803, 400.0] ]])
d=list([[ [5.273e-27, 4.440e-16, 7.175e-6, 1.669e+4] ]])

# this works
tf1=control.tf(n,d)
print(tf1)

# now with coefficients from SymPy
s=sym.symbols("s",complex=True)
np=sym.Poly(-9.762e-24*s**3 -2.283e-13*s**2 -0.0005803*s +400.0)
npc=sym.polys.Poly.all_coeffs(np)                             
dp=sym.Poly(5.273e-27*s**3 +4.440e-16*s**2 +7.175e-6*2 +1.669e+4)
dpc=sym.polys.Poly.all_coeffs(dp)                             
print(np,npc)
print(dp,dpc)

# this does not work :-(
tf2=control.tf(npc,dpc)