Which argument type does poly expect?

[ufechner7]

If I call the function poly with the following parameter it fails:

julia> denvec(sys)[]
3-element Vector{Sym}:
 1
 c
 b

julia> poly(denvec(sys)[], s)
ERROR: MethodError: no method matching getptr(::Vector{PythonCall.Py})

Closest candidates are:
  getptr(::Any)
   @ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:26
  getptr(::PythonCall.Py)
   @ PythonCall ~/.julia/packages/PythonCall/qTEA1/src/Py.jl:49

I guess I need a conversion, but how?

[jverzani]

So, poly is not exported from sympy. As you calling it with sympy.poly (where sympy comes from SymPyPythonCall? That should do the necessary conversions for you. (I believe PyCall does more to help with this than PythonCall.) Somewhere else you discussed an sp object, which parallels the internal _sympy_ object. This can also be called, as with _sympy_.poly(...). The difference is you need to manage the conversions up and down. One way to avoid that, would be to wrap your sp object, as Sym(sp).poly(....).