$ more secret.pyf
!  -*- f90 -*-
! Note: the context of this file is case sensitive.
python module secretcode ! in
  interface  ! in :secretcode
    subroutine hellofortran(n) ! in :secretcode:secret.f90
      integer :: n
    end subroutine hellofortran
  end interface
end python module secretcode
! This file was auto-generated with f2py (version:2).
! See http://cens.ioc.ee/projects/f2py2e/