You can call this line to suppress the dialog.
swApp.SetUserPreferenceToggle swUserPreferenceToggle_e.swInputDimValOnCreate, False
Please note that it is good practice to restore this value back after you finish.
Artem Taturevych, Application Engineer at Intercad (Australia)
translationXpert – add-in to translate SolidWorks models
myIntercad – an integrated tool for SolidWorks Professionals
thank you very much!