multiprocessing is a package that supports spawning processes using an API similar to the threading module. The multiprocessing package offers both local and remote concurrency, effectively side-stepping the Global Interpreter Lock by using subprocesses instead of threads. Due to this, the multiprocessing module allows the programmer to fully leverage multiple processors on a given machine. It runs on both Unix and Windows.

IBM has published a wonderful article on Multiprocessing with Python in which I have modified their snippets for my purposes below.

To leverage NetSNMP in python you need to compile it with python modules, I wrote a post about this yesterday in Compiling Netsnmp for Ubuntu. After battling through the compiling bit you should be able to get the example in the IBM post to work. I modified this example *slightly* to accommodate instance identifier (iid).  Hopefully this will be suitable for a new project I’m working on which polls thousands of snmp oids to measure latency between routers using the concept I posted on hatch – Configure RTR/SLA Ping in IOS template.

!/usr/bin/env python
"""
This is a multiprocessing wrapper for Net-SNMP.
This makes a synchronous API asynchronous by combining
it with Python2.6
"""

import netsnmp
from multiprocessing import Process, Queue, current_process

class HostRecord():
    """This creates a host record"""
    def __init__(self,
                 hostname = None,
                 query = None):
        self.hostname = hostname
        self.query = query

class SnmpSession():
    """A SNMP Session"""
    def __init__(self,
                oid = "sysDescr",
                iid="0",
                Version = 2,
                DestHost = "localhost",
                Community = "public",
                Verbose = True,
                ):
        self.oid = oid
        self.Version = Version
        self.DestHost = DestHost
        self.Community = Community
        self.Verbose = Verbose
        self.var = netsnmp.Varbind(oid, iid)
        self.hostrec = HostRecord()
        self.hostrec.hostname = self.DestHost

    def query(self):
        """Creates SNMP query

        Fills out a Host Object and returns result
        """
        try:
            result = netsnmp.snmpget(self.var,
                                Version = self.Version,
                                DestHost = self.DestHost,
                                Community = self.Community)
            self.hostrec.query = result
        except Exception, err:
            if self.Verbose:
                print err
            self.hostrec.query = None
        finally:
            return self.hostrec

def make_query(host):
    """This does the actual snmp query

    This is a bit fancy as it accepts both instances
    of SnmpSession and host/ip addresses.  This
    allows a user to customize mass queries with
    subsets of different hostnames and community strings
    """
    if isinstance(host,SnmpSession):
        return host.query()
    else:
        s = SnmpSession(DestHost=host)
        return s.query()

# Function run by worker processes
def worker(input, output):
    for func in iter(input.get, 'STOP'):
        result = make_query(func)
        output.put(result)

def main():
    """Runs everything"""

    #clients
    hosts = [
    SnmpSession(DestHost="10.71.1.1", Community="my-pub-community", oid="1.3.6.1.4.1.9.9.42.1.2.10.1.1", iid="1"),
    SnmpSession(DestHost="10.81.1.1", Community="my-pub-community", oid="1.3.6.1.4.1.9.9.42.1.2.10.1.1", iid="123")
    ]
    NUMBER_OF_PROCESSES = len(hosts)

    # Create queues
    task_queue = Queue()
    done_queue = Queue()

    #submit tasks
    for host in hosts:
        task_queue.put(host)

    #Start worker processes
    for i in range(NUMBER_OF_PROCESSES):
        Process(target=worker, args=(task_queue, done_queue)).start()

     # Get and print results
    print 'Unordered results:'
    for i in range(len(hosts)):
        print '\t', done_queue.get().query

    # Tell child processes to stop
    for i in range(NUMBER_OF_PROCESSES):
        task_queue.put('STOP')
        #print "Stopping Process #%s" % i

if __name__ == "__main__":
    main()

1. Create a twitter account twitter.com
2. Create a twitter “application’ and get your keys dev.twitter.com/apps
3. Click on “settings” and set the access to read and write
4. easy_install python-twitter
5. Use this template

Whenever you save a “Post” object, the def send_tweet method will attempt to tweet a message containing the name of the object as well as the absolute url.

tags = indexes.MultiValueField(indexed=True, stored=True)

Full Example

myproject/myapp/models.py

from django.db import models,
from tagging.fields import TagField
class Template(models.Model):
        name = models.CharField(max_length=100)
        pub_date = models.DateTimeField(editable=False, blank=True)
        description = models.TextField(blank=True)
        slug = models.SlugField(unique=True,editable=False,blank=True,null=True)
        tags = TagField()

myproject/myapp/search_indexes.py

import datetime
from haystack import indexes
from generator.models import Template

class TemplateIndex(indexes.RealTimeSearchIndex):
    text = indexes.CharField(document=True, use_template=True)
    name = indexes.CharField(model_attr='name')
    description = indexes.CharField(model_attr='description')
    pub_date = indexes.DateTimeField(model_attr='pub_date')
    tags = indexes.MultiValueField(indexed=True, stored=True)

    def get_model(self):
        return Template

    def index_queryset(self):
        """Used when the entire index for model is updated."""
        return self.get_model().objects.filter(pub_date__lte=datetime.datetime.now())

TypeError at /accounts/register/

register() takes at least 2 non-keyword arguments (1 given)

Here’s what your urls.py should look like for the /accounts/register/ url:

urls.py

from django.conf.urls.defaults import *
from registration.forms import RegistrationFormUniqueEmail

urlpatterns = patterns('',
     (r'^accounts/register/', 'registration.views.register', {'form_class':RegistrationFormUniqueEmail,'backend':'registration.backends.default.DefaultBackend' }),
)

file: /myproject/myapp/models.py

from django.contrib.auth.models import User
from sorl.thumbnail import ImageField
import datetime
import re

class Project(models.Model):
        title = models.CharField(max_length=255,blank=True)
        description = models.TextField(blank=True)
        photo = ImageField(upload_to=get_project_upload_path, blank=True, null=True)
        author = models.ForeignKey(User, editable=False,blank=True, null=True)
        pub_date = models.DateTimeField(editable=False, blank=True)
        slug = models.SlugField(unique=True,blank=True)

        def save(self, *args, **kwargs):
		#set pub_date as right now
                self.pub_date=datetime.datetime.now()

		#As long as this object does NOT have a slug
                if not self.slug:
                   from django.template.defaultfilters import slugify

		   #Take the title and replace spaces with hypens, make lowercase
                   potential_slug = slugify(self.title)
                   self.slug = potential_slug

                   while True:
                      try:
			 #try to save the object
                         super(Project, self).save(*args, **kwargs)

		      #if this slug already exists we get an error
                      except IntegrityError:
			 #match the slug or look for a trailing number
                         match_obj = re.match(r'^(.*)-(\d+)$', self.slug)

			 #if we find a match
                         if match_obj:
			    #take the found number and increment it by 1
                            next_int = int(match_obj.group(2)) + 1
                            self.slug = match_obj.group(1) + "-" + str(next_int)
                         else:
			    #There are no matches for -# so create one with -2
                            self.slug += '-2'
		      #different error than IntegrityError
                      else:
                         break

        def __unicode__(self):
                return self.title