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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def SAS(self):
 """ Set-up for the rectangularly-gridded superposition of analytical solutions method for solving flexure """

    if self.x is None:
      self.x = np.arange(self.dx/2., self.dx * self.qs.shape[0], self.dx)
    if self.filename:
      # Define the (scalar) elastic thickness
      self.Te = self.configGet("float", "input", "ElasticThickness")
      # Define a stress-based qs = q0
      self.qs = self.q0.copy()
      # Remove self.q0 to avoid issues with multiply-defined inputs
      # q0 is the parsable input to either a qs grid or contains (x,(y),q)
      del self.q0
    if self.dimension == 2:
      if self.y is None:
        self.y = np.arange(self.dy/2., self.dy * self.qs.shape[0], self.dy)
      # Define a stress-based qs = q0
      # But only if the latter has not already been defined
      # (e.g., by the getters and setters)
      try:
        self.qs
      except:
        self.qs = self.q0.copy()
        # Remove self.q0 to avoid issues with multiply-defined inputs
        # q0 is the parsable input to either a qs grid or contains (x,(y),q)
        del self.q0
      from scipy.special import kei