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Comment by hynek | Hacker News Reader

Ehm, how do you check whether an IP address is inside of a specific network with strings? Or how two networks overlap? How many addresses a network has?

Hint: there’s more than /24 networks and IPv6 makes it even more complicated.

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While I don't share the OP's worry, I'm guessing he was thinking of utility functions operating on strings as the alternative.

You can’t hide the complexity of doing that right but OTOH the ipaddress objects have useful str() methods:

  >>> str(ipaddress.ip_address('127.0.0.1'))
  '127.0.0.1'
  >>> str(ipaddress.ip_address('::1'))
  '::1'
  >>> str(ipaddress.ip_network('192.168.42.0/24'))
  '192.168.42.0/24'

But you can do stuff like:

  >>> ipaddress.ip_address('192.168.42.23') in ipaddress.ip_network('192.168.42.0/24')
  True
  >>> ipaddress.ip_address('192.168.41.23') in ipaddress.ip_network('192.168.42.0/24')
  False

  for addr in ipaddress.ip_network('192.168.42.0/24'):
      print(adds)

Etc. I strongly suggest to have a look at http://docs.python.org/dev/howto/ipaddress.html#ipaddress-ho... to have an overview over it’s functionality – unfortunately the API docs aren’t done yet, but will be for 3.3 final.

edit fixed code markup

Just for the record, I agree that the problem space is such that a utility class is warranted having written code dealing with IP addresses in the past; I was just speculating about the OP's thoughts :).

yes, just one or two utility functions would do. IMHO there is no need to initialize a class and call a method just for checking network overlap/boundaries.

no need to use it, really. you can pretend it doesn't exist. problem solved.

It's not a high overhead. Your string method would have to do basically the same thing as the ipaddress initialization and method call. As a benefit, with ipaddress you don't have to re-parse the string every time you want to manipulate it as an address; and you get a bit of typechecking and documentation from using a specialized class.

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