extracting numbers from a file, excluding fixed words

[dawenliu at gmail.com]

I've changed the code a little bit and works fine now:
inf = open('input.txt')
out = open('output.txt', 'w')

skips = [
'xxxxxxx xxxxxxxxxx xxxxx xxxxxxx',
  'yyyyy yyyyyy yyy yyyyyy yyyyy yyy']

for line in inf:
  flag = 0
  for skip in skips:
    if skip in line:
      flag = 1
      continue
  if flag == 0:
    out.write(line)

inf.close()
out.close()