CODEWITHSUNDEEP
pythonpython-3.x
PyNewbie
PyNewbie

Reputation: 33

fast Python IPv6 compaction

I'm trying to write some code that can quickly return a properly compacted IPv6 address. I've tried...

socket.inet_pton(socket.AF_INET6,socket.inet_PTON(socket.AF_INET6,address))
ipaddress.IPv6Address(address)
IPy.IP(address)

...listed from faster to slower in their speed of handling IPv6 compaction. The first is the fastest (~3.6 seconds per 65,565 IP addresses), the second is less than half as fast as the first (~8.4 seconds per 65,565 IP addresses), the last one is almost twice as slow as the second (~14.4 seconds per 65,565 IP addresses).

So, I set out to create my own...

import re
from ipaddress import IPv6Address

IPaddlist = [
    '2001:db8:00:0:0:0:cafe:1111',
    '2001:db8::a:1:2:3:4',
    '2001:0DB8:AAAA:0000:0000:0000:0000:000C',
    '2001:db8::1:0:0:0:4',
    '2001:4958:5555::4b3:ffff',
  ]

for addr in IPaddlist:
  address = ":".join('' if i=='0000' else i.lstrip('0') for i in addr.split(':'))
  address2 = (re.sub(r'(:)\1+', r'\1\1', address).lower())
  print(address2)
  print(IPv6Address(addr))
  print('\n')

It returns:

2001:db8::cafe:1111
2001:db8::cafe:1111

2001:db8::a:1:2:3:4
2001:db8:0:a:1:2:3:4

2001:db8:aaaa::c
2001:db8:aaaa::c

2001:db8::1::4
2001:db8:0:1::4

2001:4958:5555::4b3:ffff
2001:4958:5555::4b3:ffff

The first line of each entry is my code, the second is the correct compaction, using ipaddress.IPv6Address.

As you can see, I'm close, but you know what they say about 'close'...

Anyone have any pointers? I seem to have hit a roadblock.

Upvotes: 2

Views: 715

Answers (1)

skovorodkin
skovorodkin

Reputation: 10284

Just use socket functions. The first line of code in your question is almost 10 times faster than your string manipulations:

from socket import inet_ntop, inet_pton, AF_INET6
def compact1(addr, inet_ntop=inet_ntop, inet_pton=inet_pton, AF_INET6=AF_INET6):
    return inet_ntop(AF_INET6, inet_pton(AF_INET6, addr))

from ipaddress import IPv6Address
def compact2(addr, IPv6Address=IPv6Address):
    return IPv6Address(addr)

import re
def compact3(addr, sub=re.sub):
    address = ":".join('' if i=='0000' else i.lstrip('0') for i in addr.split(':'))
    return sub(r'(:)\1+', r'\1\1', address).lower()

And now let's %timeit:

In[9]: ips = [':'.join('{:x}'.format(random.randint(0, 2**16 - 1)) for i in range(8)) for _ in range(65565)]

In[10]: %timeit for ip in ips: compact1(ip)
10 loops, best of 3: 52.9 ms per loop

In[11]: %timeit for ip in ips: compact2(ip)
1 loop, best of 3: 715 ms per loop

In[12]: %timeit for ip in ips: compact3(ip)
1 loop, best of 3: 411 ms per loop

Upvotes: 1

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