Simple python script to validate HTML

validate.py

from contextlib import closing
import urllib2
import html5lib
import sys

f = urllib2.urlopen(sys.argv[1])
data = f.read()
f.close()
parser = html5lib.HTMLParser()
dociument = parser.parse(data)

errList=[]
for pos, errorcode, datavars in parser.errors:
    errList.append("Line %i Col %i"%pos + " " + html5lib.constants.E.get(errorcode, 'Unknown error "%s"' % errorcode) % datavars)

sys.stdout.write("\nValidation errors:\n" + "\n".join(errList)+"\n")