Quick script for removing NaN values from rrd files

deNaN.py

#!/usr/bin/python
# Shell usage example:
# f=somefile.rrd
# rrdtool dump $f > /tmp/$f.xml && /tmp/deNaN.py /tmp/$f.xml > /tmp/$f.xml.new && mv $f{,.bak} && rrdtool restore /tmp/$f.xml.new $f

import fileinput
import re 

lastval = ''

for line in fileinput.input():
    match = re.search(r"<row><v>(.*)<\/v><\/row>", line)
    if match:
    	match_str = match.group(1)
	if match_str == 'NaN':
            line = line.replace('NaN', lastval)
        else:
            lastval = match_str
    print line,