Page 180 - DCAP606_BUSINESS_INTELLIGENCE

Unit 12: Understanding Data Mining Tools

Notes
Developers write code at basically a constant rate so we chose Python which was (and is)
the highest level language I’ve ever seen that is also flexible enough to be generally
useful.”
Architecture

From the beginning, Timesheet was designed and implemented as a web application. It
uses three-tiered web application architecture with separate layers for web presentation,
business logic, and data storage. As time has progressed, the application’s functionality
has advanced considerably, and Curt’s decision to use Python for an implementation
language has proven to be good choice. Python is currently used for all application logic
in the Timesheet application. This includes all code between the initial Apache dispatch,
where mod_python is employed to expedite interpreter instantiation, through the
application logic, and down to the point of call out to the database transport layer. Timesheet
uses not only the Python standard library but also several independently developed open
source Python subsystems, such as PyXML and ActZero’s SOAP support. PyXML is used to
implement certain business rules and to develop jxAPI, which is a SOAP-based API into
the application logic. Work is in progress to extend this API to define Web Services
Description Language templates for the jxAPI functions. The application currently builds
and ships with Python 2.1.1. Timesheet also incorporates several non-Python technologies.
The Unix and Linux distributions are packaged with the Apache HTTP server and
PostgreSQL database. The Timesheet distribution for Windows ships with an optional
Microsoft Desktop Engine (MSDE) database and integrates with Microsoft IIS. Timesheet
can be configured to use a variety of third-party databases.
Results

The Timesheet project has succeeded spectacularly, generating millions in revenue and
allowing Journyx to grow every year, even under the current economic conditions. Journyx,
like many of our customers, uses Timesheet internally as a mission critical part of the
company infrastructure. It is used extensively for project tracking, billing, and payroll. To
date, approximately 11 person-years have gone into the Journyx Timesheet product,
resulting in over one hundred fifty thousand lines of Python code. In developing Journyx,
the two greatest benefits of Python were the speed with which features could be written
and deployed, and its true write-once-run-anywhere cross-platform capabilities. Journyx
developers have found that the simplicity and clarity of Python combine with its object-
oriented properties to make it a very powerful and productive language. Python’s rich
standard library, which includes modules for things like string manipulation and HTML
generation, further supports programmers in meeting aggressive development schedules.
Because of these properties of the language, Python has enabled Journyx to add features
more quickly than our competitors. We’ve been able to implement SOAP/XML and WSDL
support and extended other aspects of the application’s functionality well ahead of
competitive products. One of the key enablers of this efficiency in maintenance and
improvement is the inherent clarity and readability of the Python language. Other
important factors are the vibrant and responsive Python development community, and
the high degree of backwards compatibility and stability we have seen as the language
design evolves over time. Python’s cross-platform standard library and platform-
independent byte code file format allow the deployment of Python modules to any
platform, regardless of which platform the module was prepared on. This helped not only
in avoiding per-platform development overhead but also facilitates customer support for
the Timesheet software product. For example, a patch module built on a Redhat 6.2 system
can be sent to a customer for installation on Windows XP or any other operation system
without the need for cross-compilation or translation of any kind.
Contd....

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