Python, how do I drop the first octet in reverse zone? fun with strings

Question

I need to create a reverse DNS entry for IPv4.

The ip address is 108.61.190.64

But the reverse DNS entry is = each octet in reverse order with the last octet dropped

i.e.

$ORIGIN 190.61.108.IN-ADDR.ARPA.

or

12.34.56.78 ->  78.56.34.12

Is there a Python tool for this task? [::-1] does a complete reverse and not just rearranging the octets.

P.S. I have the same reverse issue for IPv6 but no octet is to be dropped.

Georgi Dimitrov · Accepted Answer · 2015-05-02T15:19:20.497

1

I guess you can do something similar to this:

>>> ip = '12.34.56.78'
>>> reversed = '.'.join(ip.split('.')[::-1])
>>> reversed
'78.56.34.12'

And if you want to drop the last one:

>>> ip = '12.34.56.78'
>>> reversed = '.'.join(ip.split('.')[::-1][:-1])
>>> reversed
'78.56.34'

edited May 02 '15 at 15:19

answered May 02 '15 at 15:12

Georgi Dimitrov

It says I have to wait a few minutes to click the button. Thank you! – mine May 02 '15 at 15:17
How would I drop the first octet? – mine May 02 '15 at 15:19
reversed = '.'.join(ip.split('.')[::-1][1:]). You might want to read more about python list slicing: http://stackoverflow.com/questions/509211/explain-pythons-slice-notation – Georgi Dimitrov May 02 '15 at 15:33
1

@mine `'.'.join(ip.split('.')[-2::-1])`. Dropping the last one can also be done with `'.'.join(ip.split('.')[:0:-1])`. – Stefan Pochmann May 02 '15 at 15:35

1 Answers1