using mod_wsgi deploy django project

1. install httpd-devel, python-devel
# yum install htppd-devel, python-devel

2. install mod_wsgi
  a. Download mod_wsgi source code. modwsgi
  b. untar & using ./configure; make; make install

3. edit /etc/httpd/conf/httpd.conf
LoadModule wsgi_module modules/mod_wsgi.so
WSGIScriptAlias /mysite /usr/local/www/mysite/apache/django.wsgi

4. Create django project
#cd /usr/local/www
#django-admin.py startproject mysite

5. create apache folder
# cd /usr/loca/www/mysite
# mkdir apache

6. Create django.wsgi file in apache folder, the content is:

import os
import sys
path = '/usr/local/www'
if path not in sys.path:
    sys.path.append(path)

os.environ['DJANGO_SETTINGS_MODULE'] = 'mysite.settings'

import django.core.handlers.wsgi
application = django.core.handlers.wsgi.WSGIHandler()

7. restart httpd

8. open brower and open link: http://localhost/mysite

Reference:
http://code.google.com/p/modwsgi/wiki/QuickInstallationGuide
http://code.google.com/p/modwsgi/wiki/QuickConfigurationGuide
https://docs.djangoproject.com/en/1.3/howto/deployment/modwsgi/

python with statement

python 2.5支援with statement,用法像這樣,以open file為例:

printf("xxxx");
with open("x.txt") as f:
  data = f.read()
  do something with data

  因為file object已經有了__enter__()和__exit__()這兩個method,利用with statement就能自動達到像是try-except-finally的程式流程

  若自定class implement __enter__(self)和__exit__(self, type, value, traceback)也能利用with statement來簡化

參考資料:
http://effbot.org/zone/python-with-statement.htm
http://effbot.org/pyref/with.htm

解決yum update perl conflict問題

若yum update perl發生
conflicts with file from package perl.x.x.x
用rpm -e移除perl.i386 (若妳的CentOS是x64)
rpm -e perl.i386
在執行yum update perl應該就不會發生conflicts了

參考資料:
http://slash4.de/tutorials/CentOS_5.4_perl_update_problem