Presentation of the API

The IP class allows a comfortable parsing and handling for most notations in use for IPv4 and IPv6 addresses and networks. It was greatly inspired by RIPE's Perl module NET::IP's interface but doesn't share the implementation. It doesn't share non-CIDR netmasks, so funky stuff like a netmask of 0xffffff0f can't be done here.

>>> from IPy import IP
>>> ip = IP('127.0.0.0/30')
>>> for x in ip:
...  print x
...
127.0.0.0
127.0.0.1
127.0.0.2
127.0.0.3
>>> ip2 = IP('0x7f000000/30')
>>> ip == ip2
1
>>> ip.reverseNames()
['0.0.0.127.in-addr.arpa.', '1.0.0.127.in-addr.arpa.', '2.0.0.127.in-addr.arpa.', '3.0.0.127.in-addr.arpa.']
>>> ip.reverseName()
'0-3.0.0.127.in-addr.arpa.'
>>> ip.iptype()
'PRIVATE'

Supports most IP address formats

It can detect about a dozen different ways of expressing IP addresses and networks, parse them and distinguish between IPv4 and IPv6 addresses:

>>> IP('10.0.0.0/8').version()
4
>>> IP('::1').version()
6

Derive network address

IPy can transform an IP address into a network address by applying the given netmask: >>> print IP('127.0.0.1/255.0.0.0', make_net=True) 127.0.0.0/8

This can also be done for existing IP instances: >>> print IP('127.0.0.1').make_net('255.0.0.0') 127.0.0.0/8

Option check_addr_prefixlen

By default, IPy rejects uncommon netmasks like 172.30.1.0/22:

>>> import IPy
>>> IPy.check_addr_prefixlen = True    # default value
>>> ips = IP('172.30.1.0/22')
Traceback (most recent call last):
  ...
ValueError: IP('172.30.1.0/22') has invalid prefix length (22)

You can change this behaviour with global option check_addr_prefixlen:

>>> IPy.check_addr_prefixlen = False   # disable
>>> ips = IP('172.30.1.0/22')
>>> len(ips)
1024

The behaviour change with global check_addr_prefixlen option:

>>> import IPy
>>> IPy.check_addr_prefixlen = True
>>> IP('0.0.0.0-0.0.0.4')
Traceback (most recent call last):
...
ValueError: the range 0.0.0.0-0.0.0.4 is not on a network boundary.
>>> IPy.check_addr_prefixlen
True

>>> IPy.check_addr_prefixlen = False
>>> IP('0.0.0.0-0.0.0.4')
IP('0.0.0.0/29')
>>> IPy.check_addr_prefixlen
False

Convert address to string

Nearly all class methods which return a string have an optional parameter 'wantprefixlen' which controls if the prefixlen or netmask is printed. Per default the prefilen is always shown if the network contains more than one address:

wantprefixlen == 0 / None     don't return anything   1.2.3.0
wantprefixlen == 1            /prefix                 1.2.3.0/24
wantprefixlen == 2            /netmask                1.2.3.0/255.255.255.0
wantprefixlen == 3            -lastip                 1.2.3.0-1.2.3.255

You can also change the defaults on an per-object basis by fiddling with the class members:

• NoPrefixForSingleIp
• WantPrefixLen

Examples of string conversions:

>>> IP('10.0.0.0/32').strNormal()
'10.0.0.0'
>>> IP('10.0.0.0/24').strNormal()
'10.0.0.0/24'
>>> IP('10.0.0.0/24').strNormal(0)
'10.0.0.0'
>>> IP('10.0.0.0/24').strNormal(1)
'10.0.0.0/24'
>>> IP('10.0.0.0/24').strNormal(2)
'10.0.0.0/255.255.255.0'
>>> IP('10.0.0.0/24').strNormal(3)
'10.0.0.0-10.0.0.255'
>>> ip = IP('10.0.0.0')
>>> print ip
10.0.0.0
>>> ip.NoPrefixForSingleIp = None
>>> print ip
10.0.0.0/32
>>> ip.WantPrefixLen = 3
>>> print ip
10.0.0.0-10.0.0.0

Compatibility and links

IPy works on Python version 2.2 to 2.5.

This Python module is under BSD license: see COPYING file.

Further Information might be available at: http://software.inl.fr/trac/trac.cgi/wiki/IPy

TODO

• better comparison (__cmp__ and friends)
• tests for __cmp__
• always write hex values lowercase
• interpret 2001:1234:5678:1234/64 as 2001:1234:5678:1234::/64
• move size in bits into class variables to get rid of some "if self._ipversion ..."
• support for base85 encoding
• support for output of IPv6 encoded IPv4 Addresses
• update address type tables
• first-last notation should be allowed for IPv6
• add IPv6 docstring examples
• check better for negative parameters
• add addition / aggregation
• move reverse name stuff out of the classes and refactor it
• support for aggregation of more than two nets at once
• support for aggregation with "holes"
• support for finding common prefix
• '>>' and '<<' for prefix manipulation
• add our own exceptions instead ValueError all the time
• rename checkPrefix to checkPrefixOk
• add more documentation and doctests
• refactor