Install PostgreSQL for Django and Virtualenv on Ubuntu

Install PostgreSQL:

sudo apt-get install postgresql

Later we need to install psycopg2 using pip. To resolve some dependency issues, we need to install libpq-dev and python-dev. For more details, please see here.

sudo apt-get install libpq-dev python-dev

Set password for the "postgres" user.

sudo passwd postgres

Then enter password.

Create a Django dev user:

sudo -u postgres createuser -P django_dev

Enter password.

Add postgres to sudoers:

sudo vi /etc/sudoers

Find the following line:

root ALL=(ALL:ALL) ALL 

Below this line, add the following:

postgres ALL=(ALL) ALL

Now switch to the "postgres" user

su postgres

Enter PostgreSQL shell:

psql postgres

Create a DB:

CREATE DATABASE django_db OWNER django_dev ENCODING 'UTF8';

Type \q to quit the PostgreSQL shell.

Edit the permission file:

sudo vi /etc/postgresql/9.1/main/pg_hba.conf

Your PostgreSQL version number might be different. Replace 9.1 with the correct version number.

Change:

local    all    postgres    peer 
local    all    all    peer

To:

local    all    postgres    md5
local    all    all    md5

And add the following line:

local    django_db    django_dev    md5

Now, restart PostgreSQL server:

sudo /etc/init.d/postgresql restart

Get into virtual env and install psycopg2:

source ~/your_virtual_env/bin/activate
pip install psycopg2

Go to your django project and edit the settings.py file, change the following settings:

'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': 'django_db', 
'USER': 'django_dev', 
'PASSWORD': 'your_password', 

Finally, at the directory where manage.py is, type the following command to synchronize DB:

python manage.py syncdb

References:

- How to install PostgreSQL on Ubuntu for Django

- PostgreSQL Ubuntu Installation

- PostgreSQL Fatal Authentication Failure

- Add User to "sudoers" File

- PostgreSQL Server Guide

Bring GVIM menu back in Ubuntu 11.10

GVIM menu bar disappeared in Ubuntu 11.10 with Unity if gvim is launched from command line. This post is a compilation of things that I tried to fix the issue.

First, you might need to remove Vim from the .gnome2 dir:

rm ~/.gnome2/Vim

Then, add the following line to ~/.bashrc

alias gvi='gvim -f'

Restart terminal. Type gvi, and you should see the gvim with menu in the unity top bar. People report that the "-f" should fix the menu problem.

If you don't want to block a terminal when opening gvim, replace the above alias line with this:

gvi() {
  gvim -f $@ &
}

Next time, when you type gvi, the gvim process will be put in background.

If you want to keep gvim running even after its terminal is closed, try this:

gvi() {
  gvim -f $@ &
  disown
}

References:

• gvim gets no global menu, timeout warning on the console
• Updated Ubuntu 11.04 from 10.x and vim's menu bar disappeared
• Linux tip: Bash parameters and parameter expansions
• How do I start a command from terminal so that terminal is not the parent?

PyDev setup for Django and Pinax development on Mac OS

Java is the primary language that I've been using on a daily basis for the past 6 years. Lately, I decided to try out Python and its web framework Django, just to keep my mind sharp and fresh.

Getting away from the Java "homeland" to a new language like Python is always challenging. Besides leaning the new syntax and framework, I've found myself stuck in choosing a productive IDE for Django development. TextMate is cool on Mac but it's not free. Vi and Emacs are strong for open source development, but it's also quite intimidating to setup, and I don't have time to divert my energy to get fluent with another IDE. I'm more interested in learning a new language and framework rather than an IDE. Coming from the Java background, it feels natural for me to work on Eclipse with a Python plugin. So I chose PyDev.

As for Pinax, it provides a collection of often-used features/apps for Django development. It is built on top of Django and 100% Django.

Pinax recommends to use virtualenv or virtualenvwrapper to isolate Python development environments, so each project can have its own libraries and dependencies, and won't affect other projects. I wrote a blog about setting up virtualenv and virtualenvwrapper on Mac if you're interested (Install pip, virtualenv, and virtualenvwrapper on Mac OS X 10.6.4).

Let's setup PyDev with Pinax and virtualenv.

PyDev plugin

I already had Eclipse installed for Java on Macbook Pro. So I just need to install PyDev plugin for Eclipse. If you haven't installed Eclipse yet, download it at: http://www.eclipse.org/downloads/?osType=macosx. I'd recommend downloading "Eclipse IDE for Java Developers" even if you don't code Java.

Untar the downloaded archive.

tar -xvf eclipse_xyz.tar.gz

Copy the "eclipse" directory to the "Application" folder, and you finished installing Eclipse.

To install PyDev plugin, select "Help->Install New Software ..." menu in Eclipse, and add PyDev update site: http://pydev.org/updates

Check the "PyDev" node and its child "PyDev for Eclipse". Click through "next" and "finish" buttons. Eclipse will resolve all dependencies and install PyDev plugin.

Setup PyDev

Stackoverflow.com already has some useful information on this topic:

The most helpful link is Vlku's screencast. Make sure you watch it, however, please also notice the following highlights:


1. For each virtual environment, you need to add a Python interpreter, and point to the correct python executable. To find out the full path of the python executable, first you need to activate the virtual environment:

workon pinax-env

Replace "pinax-env" with your virtual env name. Then, type:

which python

This will give you the full path of the python executable used by your virtual env.

Go to "Window -> Preferences -> PyDev -> Interpreter - Python". In the right pane, select the "New" button, and copy this path to the "Interpreter Executable" text box. PyDev will resolve all libraries after you press "OK".

2. PyDev will resolve libraries and list them in PYTHONPATH. You don't need to manually change the PYTHONPATH list unless the library you want to use is missing. Here I include the PyDev debug plugin at eclipse/plugins/org.python.pydev.debug_1.6.3.2010100513/pysrc. This plugin is used to debug Python programs.


3. When you create a project in PyDev, make sure it is a "PyDev project", and the project directory should be one level up above the actual project folder. For example, your project folder is "myCoolProject" under "~/workspace" directory. You can create a new directory under "~/workspace", and give it a name something like "myCoolProjectContainer". Move the "myCoolProject" folder to the "myCoolProjectContainer" directory. When you create a PyDev project, select "myCoolProjectContainer" as the project folder instead of "myCoolProject".

4. Uncheck the "Create default src folder and add it to the pythonpath" option in the project creation dialog box.


5. After the project is created, right click on the project node in "Pydev Package Explorer" and select "Properties". Go to "Pydev - PYTHONPATH", in the "Source Folders" tab, add the entire project as source folder.


6. To debug, in the "Debug Configuration" dialog box, add a new Python Run (e.g., "Debug myCoolProject").

In the "Main" tab, select "manage.py" in "Main Module".

In the "Arguments" tab, add "runserver" in the "Program arguments" text box.

Now this is important, in the "Working directory" field, check "Other" and point to the actual project directory. If you follow the example above, it will be "myCoolProject" instead of "myCoolProjectContainer" folder.

This is also important: in the "Interpreter" tab, make sure you select the correct interpreter. It should be the interpreter that you configured specially for the working virtual env.


7. To enable python debug, right click on the current perspective icon, and "customize". Select the "Command Groups Availability" tab. Check "PyDev Debug". This will put two buttons on your action bar:

- stop the debugger server
- start the pydev server

When you debug, activate "start the pydev server", and then select the debug configuration in the Debug drop down (for our example, it will be "Debug myCoolProject").


8. Vlku's screencast suggests using a special manage.py to set break points for debug. I'm not so into changing the standard manage.py. I found putting the following line in code to set breakpoints are equivalently effective.

import pydevd; pydevd.settrace()

The program will stop at the next line of the above code, and from that line, you can inspect all variables, step over, and do all the debug stuff you want.


Following the Vlku screencast and these notes, I successfully configured PyDev to work with Pinax and virtualenv on Mac. Hope this helps.

.vimrc for ruby and python

vi ~/.vimrc

set nocompatible              " Use vim defaults
"set ls=2                      " Always show status line
set showcmd                   " Show incomplete commands
set scrolloff=3               " Keep 3 lines when scrolling
set ruler                     " Show the cursor position all the time
set title                     " Show title in console title bar
set hid                       " Change buffer without saving
set showmatch                 " Show matching bracets

set ts=2                      " Numbers of spaces of tab character
set sw=2                      " Numbers of spaces to (auto)indent
set et                        " Tabs are converted to spaces, use only when required
set sts=2                     " Soft tab stop
set smartindent               " Smart indent
set autoindent
set nocindent
set wrap

set hlsearch                  " Highlight searches
set incsearch                 " Do incremental searching

if has("autocmd")
"au FileType cpp,c,java,sh,pl,php,python,ruby set autoindent
"au FileType cpp,c,java,sh,pl,php,py,rb set smartindent
au FileType cpp,c,java,sh,pl,php set cindent
au BufRead *.py set cinwords=if,elif,else,for,while,try,except,finally,def,class
au BufRead *.rb set cinwords=if,elsif,else,unless,for,while,begin,rescue,def,class,module
"au BufRead *.py set smartindent cinwords=if,elif,else,for,while,try,except,finally,def,class
"au BufRead *.rb set smartindent cinwords=if,elsif,else,unless,for,while,begin,rescue,def,class,module
endif

syntax on
"set background=dark
"hi Normal ctermfg=grey ctermbg=darkgrey
hi PreProc ctermfg=magenta
hi Statement ctermfg=darkYellow
hi Type ctermfg=blue
hi Function ctermfg=blue
hi Identifier ctermfg=darkBlue
hi Special ctermfg=darkCyan
hi Constant ctermfg=darkCyan
hi Comment ctermfg=darkGreen
au BufRead,BufNewFile *.rb hi rubySymbol ctermfg=green

For more information about syntax highlight in vi, search for the README.txt file in
/usr/share/vim/vim72/colors (the 72 could be different)

To see the list of colors for all groups, type :highlight in vi


References:

- Using Vim: Syntax Highlighting