Goal: Create a pressure on the first face of the first body for the first part.

Code:

#The following example creates a pressure on the first face of the first body for the first part.
pressure = Model.Analyses[0].AddPressure() 
part = Model.Geometry.Children  
body1 = part1.Children[0]  
face1 = body1.GetGeoBody().Faces[0]  # Get the first face of the body.
selection = ExtAPI.SelectionManager.CreateSelectionInfo(SelectionTypeEnum.GeometryEntities)  
selection.Entities = [face1]
pressure.Location = selection 
pressure.Magnitude.Inputs[0].DiscreteValues = [Quantity("0 [s]"), Quantity("1 [s]")]  
pressure.Magnitude.Output.DiscreteValues = [Quantity("10 [Pa]"), Quantity("20 [Pa]")]