So, How can we limit the size of a Subversion commitment?
The solution is quite easy, use the pre-commit hook. You can find some examples after searching around. Here’s the script that I use. It reads the tmp files in db/transactions/, caculate the total size and compare it with your settings (db/tranactions only saves changesets, not original files).

If the size exceeds your limit, the commitment fails and user will be warned with details.

#!/usr/bin/env python
#
# Limit the size of SVN commits. It reads db/transactions to caculate commit size.
# Put the follwoing 3 lines in hook/pre-commit hook like this:
#
# REPOS="$1"
# TXN="$2"
# check_commit_size.py "$REPOS" "$TXN" || exit 1
#

import sys,os,popen2

# The size is not an exact value.
MAX_BYTES = 10000000

def printUsage():
    sys.stderr.write('Usage: %s "$REPOS" "$TXN" ' % sys.argv[0])

def getTransactionSize(repos, txn):
    txnRevPath = repos+'/db/transactions'+'/'+txn+'.txn'+'/rev'
    return os.stat(txnRevPath)[6]

def checkTransactionSize(repos, txn):
    size = getTransactionSize(repos, txn)
    if (size > MAX_BYTES):
        sys.stderr.write("Sorry, you are trying to commit %d bytes, which is larger than the limit of %d.\n" % (size, MAX_BYTES))
        sys.stderr.write("If you think you have a good reason to, email to Ops and ask for permission.")
        sys.exit(1)

if __name__ == "__main__":
    #Check that we got a repos and transaction with this script
    if len(sys.argv) != 3:
        printUsage()
        sys.exit(2)
    else:
        repos = sys.argv[1]
        txn = sys.argv[2]

    checkTransactionSize(repos, txn)

We normally init a list like this “list=[]“, then how can we initialize a python list with a string variable?

Here’s my example. We created a list “a” and its initial value is ["abc"]:

Macbook-pro:~ joseph$ python
Python 2.6.1 (r261:67515, Jun 24 2010, 21:47:49)
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> a
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'a' is not defined
>>> try:
...  a.append("abc")
... except NameError:
...  a="abc".split()
...
>>> a
['abc']
>>> try:
...  a.append("abc")
... except NameError:
...  a="abc".split()
...
>>> a
['abc', 'abc']

Python is so wonderful, and I’m just a python beginner..

#!/usr/bin/python
#encoding = utf8
#Author:hysia

import sys
import socket

PORT  =  43
WhoisServers = {'com':'whois.internic.net',
              'net':'whois.internic.net',
              'org':'whois.pir.org',
              'nfo':'whois.afilias.info',
              'biz':'whois.biz',
              '.cc':'whois.nic.cc',
              'edu':'rs.internic.net',
              'mil':'whois.nic.mil',
              'gov':'whois.nic.gov',
              '.uk':'whois.nic.uk',
              '.us':'whois.nic.us',
              'ame':'whois.nic.name',
              'eum':'whois.museum',
              '.su':'whois.ripn.net',
              '.ru':'whois.nic.ru',
              'int':'whois.iana.org',
              '.ws':'whois.worldsite.ws',
              '.kr':'whois.krnic.net',
              '.jp':'whois.nic.ad.jp',
              '.it':'whois.nic.it',
              '.de':'whois.denic.de',
              '.fr':'whois.nic.fr',
              '.ca':'whois.cira.ca',
              '.cn':'whois.cnnic.net.cn',
              '.tw':'whois.twnic.net.tw',
              '.hk':'whois.hkdnr.net.hk',
              '.au':'whois.aunic.net',
              '.ac':'whois.nic.ac',
              'DEF':'whois.verisign-grs.com'}
              #'DEF':'whois.apin.net'}

fulldomain = sys.argv[1]

if fulldomain.startswith('www.'):
    fulldomain = fulldomain[4:]

domain = fulldomain[-3:]
print 'Domain: ',fulldomain
if not WhoisServers.get(domain):
    whoisserver = WhoisServers['DEF']
else:
    whoisserver = WhoisServers[domain]
print whoisserver

try:
    s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    s.connect((whoisserver,PORT))
    s.send(fulldomain + "\r\n")
    response = ''

    while True:
        data = s.recv(4096)
        response += data
        if data == '':
            break
    s.close()
    infomation = response.lower()
    try:
        pos = infomation.find('expiration date: ')
        expirDate = infomation[pos+17:pos+28]
        print 'Expiration Date:',expirDate
    except:
        print 'unkown'

except:
    print 'time out'

Looks smart! But never mind that the whois info cannot be returned correctly sometimes. I haven’t got time to look into this limitation.
The script is copied from here: http://blog.hysia.com/

#!/usr/bin/python
import random
def rand_ch_ch():
    head = random.randint(0xB0, 0xDF)
    body = random.randint(0xA, 0xF)
    tail = random.randint(0, 0xF)
    val = ( head << 0x8 ) | (body << 0x4 ) | tail
    str = "%x" % val
    return str.decode('hex').decode('gb2312')

Not sure where it is originally from. If you're the creator, please let me know.

joseph@e54:~$ python ip-whois.py 94.75.214.11
====== whois.arin.net                        

OrgName:    RIPE Network Coordination Centre
OrgID:      RIPE
Address:    P.O. Box 10096
City:       Amsterdam
StateProv:
PostalCode: 1001EB
Country:    NL

ReferralServer: whois://whois.ripe.net:43

NetRange:   94.0.0.0 - 94.255.255.255
CIDR:       94.0.0.0/8
NetName:    94-RIPE
NetHandle:  NET-94-0-0-0-1
Parent:
NetType:    Allocated to RIPE NCC
NameServer: NS-PRI.RIPE.NET
NameServer: SEC1.APNIC.NET
NameServer: SEC3.APNIC.NET
NameServer: TINNIE.ARIN.NET
NameServer: NS2.LACNIC.NET
Comment:    These addresses have been further assigned to users in
Comment:    the RIPE NCC region. Contact information can be found in
Comment:    the RIPE database at http://www.ripe.net/whois
RegDate:    2007-07-30
Updated:    2009-05-18

The source code is listed below. You may copy the code into a text file and name it as ip-query.py:

#!/usr/bin/env python
# Forwarded version from thomasfischer.biz!!!
#
import os, sys, string, time, getopt, socket, select, re, errno, copy, signal        

def queryWhois(query, server='whois.ripe.net'):
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    while 1:
        try:
            s.connect((server, 43))
        except socket.error, (ecode, reason):
            if ecode==errno.EINPROGRESS:
                continue
            elif ecode==errno.EALREADY:
                continue
            else:
                raise socket.error, (ecode, reason)
            pass
        break                                            

    ret = select.select ([s], [s], [], 30)

    if len(ret[1])== 0 and len(ret[0]) == 0:
        s.close()
        raise TimedOut, "on data"           

    s.setblocking(1)

    s.send("%sn" % query)
    page = ""
    while 1:
        data = s.recv(8196)
        if not data: break
        page = page + data
        pass

    s.close()

    if string.find(page, "IANA-BLK") != -1:
        raise 'no match'

    if string.find(page, "Not allocated by APNIC") != -1:
        raise 'no match'

    return page

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print "usage: %s " % sys.argv[0]
        sys.exit(1)
    ip = sys.argv[1]

    for server in ['whois.arin.net', 'whois.ripe.net', 'whois.apnic.net', 'whois.lacnic.net', 'whois.afrinic.net']:
        try:
            res = queryWhois(ip, server)
            print '======', server
            print res
            break # we only need the info once
        except:
            pass

If you wanna find whois information about some domain names, you might need to re-write these open-sourced scripts. An suggested alternative choice is pywhois which is hosted by code.google.com.