MacPorts Usage

Update MacPorts itself
sudo port selfupdate
sudo port -d selfupdate # debug

Updates the port tree with new versions definitions
sudo port sync

List available ports
sudo port list

Search ports
port search [keyword]

Lookup package info (desc, maintainer, etc)
port info [package]

Find package dependencies
port deps [package]

Install package
sudo port install [package]
sudo port -v install [package] #verbose

Clean out build files and tarballs
port clean --all [pakcage]

Uninstall a package
sudo port uninstall [package]

Show port contents
port contents [package]

List installed packages
port installed

List outdated ports
port outdated

Upgrade specific packages
port upgrade [package]
port upgrade outdated #updates all outdated packages


http://guide.macports.org/chunked/using.html

DJango Model Inheritance with subclasses

http://www.djangosnippets.org/snippets/1034/
http://www.djangosnippets.org/snippets/1031/
http://adam.gomaa.us/blog/2009/feb/16/subclassing-django-querysets/
http://docs.djangoproject.com/en/dev/ref/contrib/contenttypes/

Python List Operations (map, for comprehensions)

EXAMPLE 1
# Create a list
>>> l = [1,2,3,4,5,6]

# iterate through the list using a for comprehension
>>> [i for i in l]
[1, 2, 3, 4, 5, 6]

# square elements in the list using a for comprehension
>>> [i**2 for i in l]
[1, 4, 9, 16, 25, 36]

# square only even elements in the list using a for comprehension
>>> [i**2 for i in l if i % 2 == 0]
[4, 16, 36]

# iterate through the list using map
>>> map(lambda w: w, l)
[1, 2, 3, 4, 5, 6]

# square each element of the list using map
>>> map(lambda w: w**2, l)
[1, 4, 9, 16, 25, 36]

# or use map to call a separately defined function to# iterate through the list
>>> def squa(x):
...... return x**2

>>> map(squa, l)
[1, 4, 9, 16, 25, 36]

# use map function to call a separately defined function that takes 2 args
>>> l2 = map(lambda w: (w,2),l)
>>> l2
[(1, 2), (2, 2), (3, 2), (4, 2), (5, 2), (6, 2)]

>>> def pow(base, expo):
...... return base**expo

>>> map(lambda (x,y): pow(x,y), l2)
[1, 4, 9, 16, 25, 36]

# filter a list
>>> filter(lambda w: w > 2, l)
[3, 4, 5, 6]

EXAMPLE 2
# define a simple class to play with
>>> class A(object):
...... def __init__(self, x):
........ self.x = x

# create simple list of object instances of the class
>>> l = [A(1), A(2), A(3)]

# use a for (list) comprehension to iterate through the list
>>> [i.x for i in l]
[1, 2, 3]

# use a for comprehension to iterate with a condition
>>> [i.x for i in l if i.x > 1]
[2, 3]

# use map to apply a function to every element in the list
>>> map(lambda w: w.x, l)
[1, 2, 3]

>>> map(lambda w: w.x * w.x, l)
[1, 4, 9]

EXAMPLE 1

# Create a list

>>> l = [1,2,3,4,5,6]

# iterate through the list using a for comprehension

>>> [i for i in l]

[1, 2, 3, 4, 5, 6]

# square elements in the list using a for comprehension

>>> [i**2 for i in l]

[1, 4, 9, 16, 25, 36]

# square only even elements in the list using a for comprehension

>>> [i**2 for i in l if i % 2 == 0]

[4, 16, 36]

# iterate through the list using map

>>> map(lambda w: w, l)

[1, 2, 3, 4, 5, 6]

# square each element of the list using map

>>> map(lambda w: w**2, l)

[1, 4, 9, 16, 25, 36]

# or use map to call a separately defined function to# iterate through the list

>>> def squa(x):

...... return x**2

>>> map(squa, l)

[1, 4, 9, 16, 25, 36]

# use map function to call a separately defined function that takes 2 args

>>> l2 = map(lambda w: (w,2),l)

>>> l2

[(1, 2), (2, 2), (3, 2), (4, 2), (5, 2), (6, 2)]

>>> def pow(base, expo):

...... return base**expo

>>> map(lambda (x,y): pow(x,y), l2)

[1, 4, 9, 16, 25, 36]

# filter a list

>>> filter(lambda w: w > 2, l)

[3, 4, 5, 6]

EXAMPLE 3

# split a list into chunks

>>> map(None, *(iter(range(10)),) * 3)

[(0, 1, 2), (3, 4, 5), (6, 7, 8), (9, None, None)]

http://stackoverflow.com/questions/1335392/iteration-over-list-slices

Django South Migrations

Install Django South

- Place the untared 'south' folder into your Django applicaion

- Modify the project's settings.py and add 'south' to the INSTALLED_APPS list

- For new Django projects:

---1) initialize any Django apps or models to monitor with South.

----a) See Initializing Applications below

---2) run ./manage.py syncdb

---3) run ./manage.py migrate

To view help on startmigration:  # South 7.x+ uses the schemamigration command instead

./manage.py startmigration

Usage: ./manage.py startmigration appname migrationname [--initial] [--auto]

[--model ModelName] [--add-field ModelName.field_name] [--freeze] [--stdout]

Initializing Applications - needed whenever you want to track more Django apps

# this creates a 'migrations' folder in your Django app directory

./manage startmigration app_name comment --initial  # updates for South 7.x+
./manage schemamigration app_name comment --initial # Init's all models in application
./manage startmigration app_name --initial # updates for South 7.x+

./manage schemamigration app_name --initial # comment is optional here

Adding South with no data and no existing models.py objects:
# 1) syncdb as normal
python manage.py syncdb
# 2) Start an application if needed
python manage.py startapp appname
# 3) create a migration file with a blueprint to create tables
python manage.py startmigration appname --initial  # updates for South 7.x+
python manage.py schemamigration appname --initial
# 4) Apply the blueprint and create the tables
python manage.py migrate appname

# 5) Repeat steps 3 and 4 for each additional app if needed

Adding south with no data and existing models.py objects:
# 1) syncdb as normal if needed
python manage.py syncdb
# 2) create a migration file with a blueprint to create tables
python manage.py startmigration appname --initial # updates for South 7.x+
python manage.py schemamigration appname --initial
# 3) Apply the blueprint but it doesn't actually create the tables
python manage.py migrate appname --fake
# 4) Repeat steps 2 and 3 for each additional app if needed

Applying changes after making changes to a model (repeat for each app):
# Creates a migration 'blueprint' file and guesses what should take place
python manage.py startmigration appname migrationname --auto # updates for South 7.x+
python manage.py schemamigration appname migrationname --auto
# OR create the blueprint file but it will be empty
python manage.py startmigration appname migrationname  # updates for South 7.x+
python manage.py schemamigration appname migrationname
# make any modifications needed
# migrate the tables in the app
python manage.py migrate appname
# OR migrate all tables in all apps
python manage.py migrate

Adding a new model to an app already managed with south:
./manage startmigration app_name comment --model m1 --model m2 # updates for South 7.x+
./manage schemamigration app_name comment --model m1 --model m2 # inits specific models

List available migrations
python manage.py migrate --list

http://south.aeracode.org/wiki/ConvertingAnApp