points on the clock' circle are redrawn only at startup and on window resizes figure - shows the default initial pyclock display format you get when the file clock py is run directly figure - pyclock default analog display the clock hand lines are given arrows at their endpoints with the canvas line object' arrow and arrowshape options the arrow option can be firstlastnoneor boththe arrowshape option takes tuple giving the length of the arrow touching the lineits overall lengthand its width like pyviewpyclock also uses the widget pack_forget and pack methods to dynamically erase and redraw portions of the display on demand ( in response to bound eventsclicking on the clock with left mouse button changes its display to digital by erasing the analog widgets and drawing the digital interfaceyou get the simpler display captured in figure - figure - pyclock goes digital this digital display form is useful if you want to conserve real estate on your computer screen and minimize pyclock cpu utilization (it incurs very little screen update overheadleft-clicking on the clock again changes back to the analog display the analog complete gui programs