code: def _get_lambda_evaluator(self):
      fr = self.d_vars[0]
      t = self.u_interval.v
      p = self.v_interval.v
      fx = fr * cos(t) * sin(p)
      fy = fr * sin(t) * sin(p)
      fz = fr * cos(p)
      return lambdify([t, p], [fx, fy, fz])
  
imports: from sympy.utilities.lambdify import lambdify
  from sympy.core.numbers import pi
  from sympy.functions import sin, cos
  from sympy.plotting.pygletplot.plot_curve import PlotCurve
  from sympy.plotting.pygletplot.plot_surface import PlotSurface
  from math import sin
  from math import cos
label_desc: Use image node_id 2 for calling the Spherical obj's underlying member method code with example usage: obj._get_lambda_evaluator() and returns: lambdify