# Copyright 2017, 2013, 2011 Pearson Education, Inc., W.F. Punch & R.J.Enbody
import pylab
    
fp = open("epa_data.txt")
x,y = [],[]
for line in fp:
    line_lst = line.strip().split()
    x.append(int(line_lst[0]))   # year
    y.append(float(line_lst[2])) # unadjusted highway MPG
fp.close()
    
pylab.plot(x,y)
pylab.ylabel("Highway MPG")
pylab.xlabel("Year")
pylab.title("EPA annual average highway MPG data")
#pylab.show()
pylab.savefig("epa_plot.png")