A few ways to iterate over pairs of coordinates for drawing a polyline in mindsensorsUI.py

other_iteration_options.py

for i in range(len(endpoints)/2):
    actendpts.append(self.screenXFromImageCoords(endpoints[i*2],endpoints[i*2+1])) # actual x-coordinate
    actendpts.append(self.screenYFromImageCoords(endpoints[i*2],endpoints[i*2+1])) # actual y-coordinate

for i in [x * 2 for x in range(len(endpoints)/2)]: # iterate over every other integer [0, 2, 4, ...]
    actendpts.append(self.screenXFromImageCoords(endpoints[i],endpoints[i+1])) # actual x-coordinate
    actendpts.append(self.screenYFromImageCoords(endpoints[i],endpoints[i+1])) # actual y-coordinate

for (x,y) in [(endpoints[i*2],endpoints[i*2+1]) for i in range(len(endpoints)/2)]: # iterate over each pair of integers
    actendpts.append(self.screenXFromImageCoords(x,y)) # actual x-coordinate
    actendpts.append(self.screenYFromImageCoords(x,y)) # actual y-coordinate