upon request, ported my old python 2 json server example to python 3:
server.py:
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| import socketserver
import json
class MyTCPServer(socketserver.ThreadingTCPServer):
allow_reuse_address = True
class MyTCPServerHandler(socketserver.BaseRequestHandler):
def handle(self):
try:
data = json.loads(self.request.recv(1024).decode('UTF-8').strip())
# process the data, i.e. print it:
print(data)
# send some 'ok' back
self.request.sendall(bytes(json.dumps({'return':'ok'}), 'UTF-8'))
except Exception as e:
print("Exception wile receiving message: ", e)
server = MyTCPServer(('127.0.0.1', 13373), MyTCPServerHandler)
server.serve_forever() |
client.py:
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| import socket
import json
data = {'message':'hello world!', 'test':123.4}
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(('127.0.0.1', 13373))
s.send(bytes(json.dumps(data), 'UTF-8'))
result = json.loads(s.recv(1024).decode('UTF-8'))
print(result)
s.close() |
simple and handy for embedded systems
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| function startConsole()
while true
do
io.write("> ")
io.flush()
line = io.read()
if(line == "exit" or line == "quit") then break end
local func, err = loadstring(line)
if func then
local ok, result = xpcall(func, debug.traceback)
if not ok then
print("Error: "..result)
end
else
print("Error: "..err)
end
end
end
startConsole() |
so, very, very condensed example (see this as well):
UPDATE: thanks to estama, now with proper socket line reading 
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| import socket
s = socket.socket()
s.connect(('irc.rigsofrods.org', 6667))
s.send("NICK F00bar\r\n")
s.send("USER F00bar F00bar F00bar :F00bar\r\n")
connected = False
f = s.makefile('r', 4096)
while True:
data = f.readline().strip()
print data
if data.find('PING') != -1:
s.send('PONG :' + data.split(':')[1])
if not connected:
connected = True
s.send("PRIVMSG R : Login <>")
s.send("MODE F00bar +x")
s.send("JOIN #bla")
s.send('PRIVMSG #bla hello world!')
f.close() |
Its actually quite easy, as the IRC protocol is in plain text and not too complicated. Example Implementation:
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| import socket
class IRCClient:
socket = None
connected = False
nickname = 'RowBot'
channels = ['#foobar', '#barefoot']
def __init__(self):
self.socket = socket.socket()
self.socket.connect(('irc.rigsofrods.org', 6667))
self.send("NICK %s" % self.nickname)
self.send("USER %(nick)s %(nick)s %(nick)s :%(nick)s" % {'nick':self.nickname})
while True:
buf = self.socket.recv(4096)
lines = buf.split("\n")
for data in lines:
data = str(data).strip()
if data == '':
continue
print "I<", data
# server ping/pong?
if data.find('PING') != -1:
n = data.split(':')[1]
self.send('PONG :' + n)
if self.connected == False:
self.perform()
self.connected = True
args = data.split(None, 3)
if len(args) != 4:
continue
ctx = {}
ctx['sender'] = args[0][1:]
ctx['type'] = args[1]
ctx['target'] = args[2]
ctx['msg'] = args[3][1:]
# whom to reply?
target = ctx['target']
if ctx['target'] == self.nickname:
target = ctx['sender'].split("!")[0]
# some basic commands
if ctx['msg'] == '!help':
self.say('available commands: !help', target)
# directed to the bot?
if ctx['type'] == 'PRIVMSG' and (ctx['msg'].lower()[0:len(self.nickname)] == self.nickname.lower() or ctx['target'] == self.nickname):
# something is speaking to the bot
query = ctx['msg']
if ctx['target'] != self.nickname:
query = query[len(self.nickname):]
query = query.lstrip(':,;. ')
# do something intelligent here, like query a chatterbot
print 'someone spoke to us: ', query
self.say('alright :|', target)
def send(self, msg):
print "I>",msg
self.socket.send(msg+"\r\n")
def say(self, msg, to):
self.send("PRIVMSG %s :%s" % (to, msg))
def perform(self):
#self.send("PRIVMSG R : Register <>")
self.send("PRIVMSG R : Login <>")
self.send("MODE %s +x" % self.nickname)
for c in self.channels:
self.send("JOIN %s" % c)
# say hello to every channel
self.say('hello world!', c)
IRCClient() |
This is a stripped down version with no error checking or exception handling to come to the point.
So, you want to exchange data over the network between two python programs in JSON format? Or just send or receive data in JSON? No problem:
server.py:
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| import SocketServer
import json
class MyTCPServer(SocketServer.ThreadingTCPServer):
allow_reuse_address = True
class MyTCPServerHandler(SocketServer.BaseRequestHandler):
def handle(self):
try:
data = json.loads(self.request.recv(1024).strip())
# process the data, i.e. print it:
print data
# send some 'ok' back
self.request.sendall(json.dumps({'return':'ok'}))
except Exception, e:
print "Exception wile receiving message: ", e
server = MyTCPServer(('127.0.0.1', 13373), MyTCPServerHandler)
server.serve_forever() |
client.py:
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| import socket
import json
data = {'message':'hello world!', 'test':123.4}
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(('127.0.0.1', 13373))
s.send(json.dumps(data))
result = json.loads(s.recv(1024))
print result
s.close() |
simple, eh? 
Imagine, you have a huge python dict that you want to access. Usually it ends up looking like this:
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| d = {"foo":"bar","key":"value"}
print d['foo']
print d['key'] |
So, if you query that dict lots of times, the [''] will kind of get in the way for readability. So the solution could be using this wrapper class:
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| class DictObjectProxy():
obj = None
def __init__(self, obj):
self.obj = obj
def __getattr__(self, name):
if not name in self.obj:
return ""
return self.obj[name]
d = {"foo":"bar","key":"value"}
d = DictObjectProxy(ar)
print d.foo
print d.key |
looks far more clean IMHO
(also, take care of what happens when they key is not known)
How to set up debian squeeze as domU. Replace irc with the desired name
execute on dom0:
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| mkdir /mnt/target
lvcreate -L 20G vg -nirc
lvcreate -L 2G vg -nirc_swap
mkfs.ext3 /dev/vg/irc
mkswap /dev/vg/irc_swap
mount /dev/vg/irc /mnt/target
cd /mnt/target
debootstrap squeeze . http://ftp.us.debian.org/debian |
configuring:
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| vi etc/fstab
vi etc/network/interfaces
chroot . /bin/bash
passwd |
basic installation fixup:
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| apt-get remove vim-tiny
apt-get install vim ctags vim-doc vim-scripts
exit
umount /mnt/target |
(fix up before pasting!)
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| # -*- mode: python; -*-
kernel = "/boot/vmlinuz-X-xen-amd64"
ramdisk = "/boot/initrd.img-X-xen-amd64"
memory = 512
name = 'irc'
hostname = name + ".yourdomain.com"
vif = [
'ip=<IPV6> <IPV4>,mac=<MAC>',
'ip=<IPV4_internal>,mac=<MAC>'
]
disk = [
'phy:/dev/vg/'+name+' ,sda1,w',
'phy:/dev/vg/'+name+'_swap,sda2,w'
]
root = "/dev/sda1 ro"
vcpus = "1"
cpus="3"
extra = "xencons=tty console=xvc0 barrier=0 clocksource=jiffies" |
boot the new machine:
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| xm create -c irc
#after logging in:
vi /etc/hostname
hostname <>
apt-get install openssh-server
# install more software now :) |
now how to install qwebirc, in case you want that
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| apt-get install python python-twisted python-twisted-bin python-twisted-core python-twisted-runner python-twisted-names python-twisted-mail python-twisted-words python-twisted-web python-zope.interface python-openssl openjdk-6-jdk mercurial
cd /opt/
hg clone http://hg.qwebirc.org/qwebirc/
cp config.py.example config.py
vi config.py
# fix your config up!
python compile.py
# start it up on port 80 :)
python run.py -p 80
# visit your ip in your browser |
and done, have fun
I wanted to integrate a simple Youtube views and comments counter into my website.
Turned out, there was no simple solution to this problem.
So i created a little service that enables you to do exactly this: http://ytcounter.com
Live Example:
Our video got .
The other videos got .
i wanted to compare the speed of the cpp and java version of ZXing.
So after fixing some general linux related bugs, it seems to work well as start:
(the following only works with SVN rev. 2218, could be slightly different for later revisions)
0. install the Android NDK
1. check out zxing:
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| svn checkout http://zxing.googlecode.com/svn/trunk/ zxing-read-only
cd zxing-read-only |
2. fix linux bugs:
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| wget http://thomasfischer.biz/wp-content/2012/03/linux-fixes.diff
patch -p0 < linux-fixes.patch |
3. setup JNI:
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| mkdir jni
wget http://thomasfischer.biz/wp-content/2012/03/android-jni.diff
patch -p0 < android-jni.diff |
4. build it:
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| cd android
export NDKHOME=/your/ndk/path/android-ndk-r7b/
ndk-build -j8 |
i contacted some author of the lib, maybe this will go upstream,
have fun
