Antelope Love Fan

I mentioned briefly last week that I was getting started with CherryPy and how impressed I was with the ease of the install. I also finally figured out that Ubuntu has a psycopg package (python-psycopg), although I still couldn’t get web.py to work with it.

Here’s a list of the packages that I had to install on my Ubuntu 9.0.4 server to get CherryPy running

apt-get install python
apt-get install python-setuptools
apt-get install flup
apt-get install postgres
apt-get install postgresql postgresql-client postgresql-contrib
apt-get install pgdb
apt-get install postgresql-python
apt-get install python-pygresql
apt-get install gcc
apt-get install g++
apt-get install postgresql-dev
apt-get install libpq-dev
apt-get install python-psycopg

Want to get a “Hello World” example of CherryPy working? It’s incredible easy, especially if you use CherryPy’s built-in webserver (which seems like it’ll handle the sort of loads I’m going to be dealing with).

Here’s the code:

import cherrypy

cherrypy.config.update( {'server.socket_host': '127.0.0.1',
                        'server.socket_port':  80,
                        })

class HelloWorld:
        def index(self):
            return "Hello World"
        index.exposed = True

cherrypy.quickstart(HelloWorld())

Then, as root, run the following command to start the built-in webserver (assuming the code above is in the file /var/www/hello.py):

python /var/www/hello.py

If all goes well, you should see something like this:

[16/Jun/2009:21:08:00] ENGINE Listening for SIGHUP.
[16/Jun/2009:21:08:00] ENGINE Listening for SIGTERM.
[16/Jun/2009:21:08:00] ENGINE Listening for SIGUSR1.
[16/Jun/2009:21:08:00] ENGINE Bus STARTING

Go to http://localhost in your browser and you should see the text “Hello World.”

And here’s a quick database example that connects to a PostgreSQL database called testdb with a single table called todo.

CREATE TABLE todo (
    id integer NOT NULL,
    title text,
    created timestamp without time zone DEFAULT now(),
    done boolean DEFAULT false
);

INSERT INTO todo (id, title, created, done) VALUES (1, 'Learn CherryPy', '2009-06-15 11:31:38.106307', false);

import cherrypy
import psycopg
import sys

cherrypy.config.update( {'server.socket_host': '10.0.0.4',
                        'server.socket_port':  80,
                        })

class HelloWorld:
        def index(self):
            conn = psycopg.connect('dbname=testdb', 'user=myuser', 'password=mypass')
            mark = conn.cursor()
            mark.execute('SELECT * FROM todo');
            rec = mark.fetchall()

            body = ''
            for row in rec:
                body += str(row)

            return body
        index.exposed = True

cherrypy.quickstart(HelloWorld())

That’s a very basic intro to CherryPy. The complete documentation has lots of great stuff and I’ll be back to write more about it after I’ve had a chance to write something real.