search and then replace

[Flbill Blipf]

Hi,

I can't figure out how to do search, then something, then
replace. I'm hoping someone will tell me I'm being too
complicated with this code. I should be using a parser for
this, but that's beside the point.

The idea is that I want to put <xref rid=...> inside,
<name>, but only when <name> is in <front>. RID is
grabbed from a dictionary keyed on names. So, I grab all
of <front> and do search and replace for each <name> in
<front>:

# I can assume that all of <front> will be on a single
# line.
#
# lines and ids_by_name are global
def wiggle_snoot():
  name_rex = re.compile('<name>(.*?)</name>')
  front_rex = re.compile('<front>(.*?)</front>')
  split_line = [0,0,0]
  split_sub = [0,0,0]
  for i in range(0, len(lines)):
    m = front_rex.search(lines[i])
    if not m: continue
    
    split_line[0] = lines[i][:m.start()]
    split_line[1] = lines[i][m.start():m.end()]
    split_line[2] = lines[i][m.end():]
      
    start = 0
    while 1:
      m = name_rex.search(split_line[1], start)
      if not m: break

      split_sub[0] = split_line[1][:m.start()]
      split_sub[1] = split_line[1][m.start():m.end()]
      split_sub[2] = split_line[1][m.end():]
      
      if ids_by_name.has_key(m.group(1)):
        split_sub[1] = ('%s%s%s' %
                ('<name><xref rid="%s">' %
                 (ids_by_name[m.group(1)]),
                 m.group(1),
                 '</xref></name>'))
      split_line[1] = join(split_sub, '')
      start = len(split_sub[0]) + len(split_sub[1])
    lines[i] = join(split_line, '')