code: def A_cylinder(D, L):
      r'''Returns the surface area of a cylinder.
  
      .. math::
          A = \pi D L + 2\cdot \frac{\pi D^2}{4}
  
      Parameters
      ----------
      D : float
          Diameter of the cylinder, [m]
      L : float
          Length of the cylinder, [m]
  
      Returns
      -------
      A : float
          Surface area [m]
  
      Examples
      --------
      >>> A_cylinder(0.01, .1)
      0.0032986722862692833
      '''
      cap = pi*D**2/4*2
      side = pi*D*L
      A = cap + side
      return f A_cylinder(D, L):
      r'''Returns the surface area of a cylinder.
  
      .. math::
          A = \pi D L + 2\cdot \frac{\pi D^2}{4}
  
      Parameters
      ----------
      D : float
          Diameter of the cylinder, [m]
      L : float
          Length of the cylinder, [m]
  
      Returns
      -------
      A : float
          Surface area [m]
  
      Examples
      --------
      >>> A_cylinder(0.01, .1)
      0.0032986722862692833
      '''
      cap = pi*D**2/4*2
      side = pi*D*L
      A = cap + side
      return A
docs: r'''Returns the surface area of a cylinder.
  
      .. math::
          A = \pi D L + 2\cdot \frac{\pi D^2}{4}
  
      Parameters
      ----------
      D : float
          Diameter of the cylinder, [m]
      L : float
          Length of the cylinder, [m]
  
      Returns
      -------
      A : float
          Surface area [m]
  
      Examples
      --------
      >>> A_cylinder(0.01, .1)
      0.0032986722862692833