Building Emacs 24 on Ubuntu 11.10

You can install emacs24 from the Damien Cassou's repository for emacs-snapshot packages. However, I wanted to try building emacs 24 myself from source. I started off from instructions here and had to install a few additional packages to get all the build dependencies.

# Get emacs source
sudo apt-get install bzr
bzr branch bzr://bzr.savannah.gnu.org/emacs/trunk emacs

# some dependencies
sudo apt-get install libgtk-3-dev
sudo apt-get install libgif-dev libxpm-dev

# for makeinfo
sudo apt-get install texinfo

# configure complains about missing libtiff
sudo apt-get install libtiff4-dev

# configure and build (WARNING: This is to build with gtk3 as suggested in the original post)
cd emacs
./autogen.sh
./configure --with-x-toolkit=gtk3
make
src/emacs

And hurray !

Pymongo to connect with Mongolab

Mongolab provides hosting of Mongodb databases including a free plan with upto 240 MB usage. It took a little searching around to find how to use pymongo to interact with a database on mongolab. So here is some demo code for future reference. Tested with Python 2.6 and pymongo 1.7 on Ubuntu 10.10.

	#!/usr/bin/python
	# Raja Selvaraj <rajajs at gmail>
	"""
	Demonstrate use of pymongo to connect to a mongodb database on a hosted server,
	specifically mongolab
	"""
	# Use a database already created on mongolab
	server = 'xxxxx.mongolab.com'
	port = xxxxx
	db_name = 'xxxx'
	username = 'xxxxx'
	password = 'xxxxxx'
	from pymongo import Connection
	# what versions are we using
	import sys
	print 'Python version', sys.version
	import pymongo
	print 'Pymongo version', pymongo.version
	##
	# connect to server
	print '\nConnecting ...'
	conn = Connection(server, port)
	# Get the database
	print '\nGetting database ...'
	db = conn[db_name]
	# Have to authenticate to get access
	print '\nAuthenticating ...'
	db.authenticate(username, password)
	# Get the documents
	posts = db.posts
	print '\nNumber of posts', posts.find().count()
	# Remove all old posts
	posts.remove()
	print '\nNumber of posts after removal', posts.find().count()
	# Let us add one post
	post = {'Name' : 'Human',
	'Heart rate' : 60,
	'Longevity' : 70,
	'tags' : ['domestic', 'omnivore']}
	posts.insert(post)
	print '\nNumber of posts after first insert', posts.find().count()
	# Bulk inserts
	new_posts = [{'Name': 'Cat',
	'Heart rate' : 150,
	'Longevity' : 15,
	'tags' : ['domestic', 'carnivore']},
	{'Name' : 'Small dog',
	'Heart rate' : 100,
	'Longevity' : 10,
	'tags' : ['domestic', 'omnivore']},
	{'Name' : 'Medium Dog',
	'Heart rate' : 90,
	'Longevity' : 15,
	'tags' : ['domestic', 'omnivore']},
	{'Name' : 'Large dog',
	'Heart rate' : 75,
	'Longevity' : 17,
	'tags' : ['domestic', 'omnivore']},
	{'Name' : 'Chicken',
	'Heart rate' : 275,
	'Longevity' : 15,
	'tags' : ['domestic', 'omnivore']},
	{'Name' : 'Elephant',
	'Heart rate' : 30,
	'Longevity' : 70,
	'tags' : ['wild', 'herbivore']},
	{'Name' : 'Giraffe',
	'Heart rate' : 65,
	'Longevity' : 20,
	'tags' : ['wild', 'herbivore']}]
	posts.insert(new_posts)
	print '\nNumber of posts after bulk insert', posts.find().count()
	## Querying
	# Let us see all the posts
	print '\nAll posts'
	for post in posts.find():
	print post
	# find_one
	print '\nOne post only'
	print posts.find_one()
	# Find animals with heart rate > 100
	print '\nAnimals with heart rate more than 100'
	for post in posts.find({'Heart rate' : {"$gt" : 100}}):
	print post
	# Find animals with longevity between 20 and 70 (inclusive)
	print '\nAnimals with longevity between 20 and 70 (inclusive range)'
	for post in posts.find({'Longevity' : {"$gte" : 20, "$lte" : 100}}):
	print post
	# create an index to speed up queries
	# using ensure_index instead would create an index only if it does not exist
	print '\nCreating index for heart rate'
	posts.create_index("Heart rate")
	# Find by name - string matching
	print '\nRetrieve entry for elephant'
	print posts.find_one({'Name' : 'Elephant'})
	# Regex matching to find substring
	print '\nRetrieve entries for all dogs'
	for post in posts.find({'Name' : {'$regex' : 'dog'}}):
	print post
	# Do same with more regex options
	print '\nRetrieve entries for all dogs by using case insensitive matching'
	import re
	regex = re.compile('dog', re.IGNORECASE)
	for post in posts.find({'Name' : regex}):
	print post
	# Query for tags
	print '\nRetrieve entries for all domestic omnivores'
	for post in posts.find({'tags' : {'$all' : ['domestic', 'omnivore']}}):
	print post
	# close the connection
	print '\nClosing the connection'
	conn.disconnect()
	## References
	##
	# 1. http://api.mongodb.org/python/current/tutorial.html
	# 2. http://www.mongodb.org/display/DOCS/Advanced+Queries
	# 2. http://stackoverflow.com/questions/3483318/performing-regex-queries-with-pymongo
	# 3. Data for posts - http://www.sjsu.edu/faculty/watkins/longevity.htm

view raw mongolab_demo.py hosted with ❤ by GitHub