def polygon_under_graph(xlist, ylist):
 return (([(xlist[0], 0.0)] + list(zip(xlist, ylist))) + [(xlist[(-1)], 0.0)])

def polygon_under_graph ( xlist , ylist ) : return ( ( [ ( xlist [ 0 ] , 0.0 ) ] + list ( zip ( xlist , ylist ) ) ) + [ ( xlist [ ( - 1 ) ] , 0.0 ) ] )
construct the vertex list which defines the polygon filling the space under the line graph .