Homework_1

gistfile1.py

import re

error = re.compile("<(kernel|initrd|cmdline)>.*$")
boot = re.compile("<boot dev='hd'/>.*$")

fr = open('input.xml','r')
fw = open('output.xml','w')


not_change = True
exist = False

for i in fr:
	if boot.search(i) != None:
		not_change = False


fr.close()
fr = open('input.xml','r')

if not exist:
	for line in fr:
		if error.search(line) == None:
			fw.write(line)
		else:
			if (not_change): 
				line = error.sub("<boot dev='hd'/>",line)
				fw.write(line)
				not_change = False

fw.close()
fr.close()