vlib 0.5

vlib core libraries

Python Application Development - Core Classes

__Modules:__

* Configuration File Support

* Database Support

* Logging Support

* Emailing Support

* Object-like syntax for Dictionaries (odict)

__Details:__


* Configuration Module

Usage:

# To create a singleton instance of configuration data
# found in a yaml file pointed to by an environment
# variable called VCONF

from vlib import conf
conf_ = conf.getInstance()

# Print configuration data, from a Yaml file that looks
# like this:
#
# mojo:
# color: read
# size: 15

print conf_.mojo.color

# Real world example with Objects

from vlib import conf
class Foo(object):
def __init__(self):
self.conf = conf.getInstance()
webserver = self.conf.webserver
dbname = self.conf.db.name


* Database Module

Usage:

# To setup the Db instance, you need to define the following
# in your config file pointed to by the VCONF environement var
#
# database:
# engine: mysql
# host: localhost
# db: vlibtests
# user: vlibtests
# passwd: bogangles

from vlib import db
mydb = db.getInstance()

for row in mydb.query('select * from product_types'):
print row['product_type_id']
print row['name']

# Without using config

from vlib import Db
mydb = Db({'engine':'mysql',
'host':'db1',
'db':'books',
'user':'bookmgr',
'passwd':'mepassword',
'dictcursor':True })

# Real world example with Objects
# Set VCONF env var (conf module above)
# $ export VCONF=$HOME/proj/conf/dev.yml

from vlib import db
class Foo(object):
def __init__(self):
self.db = db.getInstance()
def getBook(self, book_id):
sql = 'select * from books where book_id = %s' % book_id
results = self.db.query(sql)
if results:
return results[0]
return []

* Logging Module

Usage:

# To setup a Logging instance, you need to define the following
# in your config file:
#
# logging:
# filename: /var/log/myapp/myapp.log
# level: DEBUG

# If you want the logger to email you on 'critical' you need
# define email server
#
# email:
# server : smtp.gmail.com:587
# username: [e-mail]
# password: secret
# fromaddr: Myapp Admin [e-mail]

from vlib import logger

class MyClass:

def __init__(self):
self.logger = logger.getLogger(self.__class__.__name__)

def do_something(self):
self.logger.debug('Started MyClass.do_something()')
self.logger.info('Did Something')
self.logger.warn('Warning')
self.logger.error('Did not do something')

# The following we send email:
# self.logger.critical('Something bad happened')

MyClass().do_something()

# Outputs the following in the log:
2014-02-24 14:41:30 dev1.localdomain DEBUG MyClass Started MyClass.do_something()
2014-02-24 14:41:30 dev1.localdomain INFO MyClass Did Something
2014-02-24 14:41:30 dev1.localdomain WARNING MyClass Warning
2014-02-24 14:41:30 dev1.localdomain ERROR MyClass Did not do something