import os
class gnuplot:
	def __init__(self):
		print "opening new gnuplot session..."
		self.session = os.popen("gnuplot","w")
	def __del__(self):
		print "closing gnuplot session..."
		self.session.close()
	def send(self, cmd):
		self.session.write(cmd+'\n')
		self.session.flush()

if __name__=="__main__":
	print "Single-window output:"
	g = gnuplot()
	g.send("plot sin(x)")
	g.send("replot cos(x)")
	raw_input("press ENTER to continue")
	del g

	print "Multiple window output:"
	g1 = gnuplot()
	g2 = gnuplot()
	g1.send("plot sin(x)")
	g2.send("plot cos(x)")
	raw_input("press ENTER to continue")
	del g1
	del g2