regular expression back references

[John Machin]

On Fri, 8 Aug 2003 20:40:27 -0600, "Andrew Dalke"
<adalke at mindspring.com> wrote:

>Clay Shirky
>>     # use regexes to see what to split on
>>     if re.search(":", new_address):
>
>or use
>    if ":" in new_address:
>
>>     elif re.search("-", new_address):
>>         new_list = new_address.split("-")
>>     elif re.search(".", new_address):
>>         new_list = new_address.split(".")
>
>and include a
>    else:
>        raise Exception("I have no idea what you're asking for")
>
>and maybe some ValueError catching in the int call.
>

instead maybe something like 
   new_list = []
   for sep in '-.:':
      if sep in new_address:
         new_list = new_address.split(sep)
         break
   if len(new_list) != 6:
      raise .......

plus also a test that each octet is in range(256) ....