For Systems Engineers coming in from PHP world, installing and configuring the software stack needed to run python + django applications can be a daunting task specially when dealing with multiple python versions. Or, when the operating system python version is not compatible with what is required by the python web application. Here's how I did it with Ubuntu:

1. Set locale and timezone

   locale-gen en_US.UTF-8
   echo "Asia/Singapore" >  /etc/timezone
   dpkg-reconfigure --frontend noninteractive tzdata

2. Update packages

   apt-get update && apt-get upgrade -y

3. Limits

   ulimit -n 20000
   echo 'fs.file-max = 200000' >> /etc/sysctl.d/20_nginx.conf

4. Install nginx

   apt-get install nginx -y
    
   cat << 'EOF' > /etc/nginx/nginx.conf
   user  www-data;
   worker_processes  1;
   worker_rlimit_nofile 200000;
    
   error_log  /var/log/nginx/error.log;
   pid        /var/run/nginx.pid;
    
   events {
       worker_connections  1024;
   }
    
   http {
    
       open_file_cache max=200000 inactive=20s; 
       open_file_cache_valid 30s; 
       open_file_cache_min_uses 2;
       open_file_cache_errors on;
       sendfile       on;
       tcp_nopush     on;
       tcp_nodelay    on;
       keepalive_timeout  65;
       reset_timedout_connection on;
       client_body_timeout 10;
       send_timeout 5;
    
       include       /etc/nginx/mime.types;
       default_type  application/octet-stream;
    
       log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                         '$status $body_bytes_sent "$http_referer" '
                         '"$http_user_agent" "$http_x_forwarded_for"';
       access_log /var/log/nginx/access.log main;
    
       server {
           listen       80;
           server_name  localhost;
    
           location / {
     include /etc/nginx/uwsgi_params;
     uwsgi_pass unix://var/run/uwsgi/app/app/app.sock;
           }
    
           error_page  404              /404.html;
           location = /40x.html {
               root   /usr/share/nginx/html;
           }
    
           error_page   500 502 503 504  /50x.html;
           location = /50x.html {
               root   /usr/share/nginx/html;
           }
    
           location ~ /\.ht {
               deny  all;
           }
       }
    
   }
   EOF

5. Install and config virtualenv

   apt-get install python-virtualenv virtualenvwrapper -y
   mkdir /var/webapps
   virtualenv /var/webapps/Env1
    
   # Or, if you have an alternate python version
   virtualenv -p python3 /var/webapps/Env2
    
   cat << 'EOF' >> /root/.bashrc
   export WORKON_HOME=/var/webapps
   source /etc/bash_completion.d/virtualenvwrapper
   EOF

6. Install and config uWSGI

   apt-get install uwsgi uwsgi-plugin-python -y
    
   cat << EOF > /etc/uwsgi/apps-available/app.ini
   [uwsgi]
   plugin = python
   socket = /var/run/uwsgi/app/app/%n.sock
   stats = 127.0.0.1:3000
   pythonpath = /var/webapps/sample_proj/current
   home = /var/webapps/Env1
   env = DJANGO_SETTINGS_MODULE=helloworld.settings
   module = django.core.handlers.wsgi:WSGIHandler()
   master = true
   processes = 4
   harakiri = 60
   reload-mercy = 8
   max-requests = 2000
   limit-as = 512
   reload-on-as = 256
   reload-on-rss = 192
   no-orphans = true
   vacuum = true
   touch-reload = /var/run/uwsgi/app/%n
   EOF
    
   ln -s /etc/uwsgi/apps-available/app.ini /etc/uwsgi/apps-enabled/
    
   # To restart uwsgi, just do:
   touch /var/run/uwsgi/app/app

7. Optional. Install python modules

   exit
   sudo su
   workon Env1
   pip install django 

8. Sample django app

   cd /tmp
   wget https://github.com/django-ve/helloworld/archive/master.zip
   mkdir -p /var/webapps/sample_proj/current
   unzip master.zip && cp -a helloworld-master/* /var/webapps/sample_proj/current/
   cd /var/webapps/sample_proj/current/
   python manage.py syncdb

9. Folder structure should look like

   (Env1)[email protected]:~# ls -la /var/webapps/sample_proj/current/
   total 68
   drwxr-xr-x 4 root root  4096 Feb 10 19:28 .
   drwxr-xr-x 3 root root  4096 Feb 10 19:07 ..
   drwxr-xr-x 2 root root  4096 Jun 12  2012 docs
   drwxr-xr-x 3 root root  4096 Feb 10 19:59 helloworld
   -rw-r--r-- 1 root root 35840 Feb 10 19:10 helloworld.db
   -rw-r--r-- 1 root root   253 Jun 12  2012 manage.py
   -rw-r--r-- 1 root root  1366 Jun 12  2012 README.rst
   -rw-r--r-- 1 root root  1216 Jun 12  2012 setup.py

10. Start services

    service uwsgi start && service nginx start

11. If you need a non-django sample hello world app

    import os
    import sys
     
    sys.path.append('/var/webapps/sample_proj/current')
     
    os.environ['PYTHON_EGG_CACHE'] = '/var/webapps/sample_proj/current/.python-egg'
     
    def application(environ, start_response):
        status = '200 OK'
        output = 'Hello World!'
     
        response_headers = [('Content-type', 'text/plain'),
                        ('Content-Length', str(len(output)))]
        start_response(status, response_headers)
     
        return [output]