code: def get_z_variable(nc):
      '''
      Returns the name of the variable that defines the Z axis or height/depth
  
      :param netCDF4.Dataset nc: netCDF dataset
      '''
      axis_z = nc.get_variables_by_attributes(axis='Z')
      if axis_z:
          return axis_z[0].name
      valid_standard_names = ('depth', 'height', 'altitude')
      z = nc.get_variables_by_attributes(standard_name=lambda x: x in valid_standard_names)
      if z:
          return z[0].name
      returf get_z_variable(nc):
      '''
      Returns the name of the variable that defines the Z axis or height/depth
  
      :param netCDF4.Dataset nc: netCDF dataset
      '''
      axis_z = nc.get_variables_by_attributes(axis='Z')
      if axis_z:
          return axis_z[0].name
      valid_standard_names = ('depth', 'height', 'altitude')
      z = nc.get_variables_by_attributes(standard_name=lambda x: x in valid_standard_names)
      if z:
          return z[0].name
      return
docs: Returns the name of the variable that defines the Z axis or height/depth
  
      :param netCDF4.Dataset nc: netCDF dataset