def midpt(*args):
xs,ys = 0,0
for p in args:
xs += p[0]
ys += p[1]
return xs/len(args),ys/len(args)
def distsum(*args):
return sum([ ((args[i][0]-args[i-1][0])**2 + (args[i][1]-args[i-1][1])**2)**0.5 for i in range(1,len(args))])