# OCC.Display.SimpleGui module

`check_callable`(_callable)

`init_display`(backend_str=None, size=(1024, 768))

  This function loads and initialize a GUI using either wx, pyq4, pyqt5 or pyside. If ever the environment variable PYTHONOCC_SHUNT_GUI, then the GUI is simply ignored. It can be useful to test some algorithms without being polluted by GUI statements. This feature is used for running the examples suite as tests for pythonocc-core development.