In this tutorial I am going to give you a gentle introduction to network programming in Python. If you are new to programming or new to Python then that may seem like a daunting thought. But read on and you will be pleasantly surprised how easy it is.

Like most modern programming languages, Python was designed for networking from the very beginning, and thanks to that, a lot of the networking tasks you would want to accomplish with the language are made a whole lot easier.

Network communication is a large topic, but if it is something that interests you then read on because in this tutorial I will show you how to download a web page. I will show you how easy Python makes tasks like this.

Take a look at the following code:

import urllib
	
con = urllib.urlopen("http://hartmannsoftware.com")
page = con.read()
con.close()
print page

I suspect that many of you are familiar with the term "hard coding a value" whereby the age of an individual or their location is written into the condition (or action) of a business rule (in this case) as shown below:

if customer.age > 21 and customer.city == 'denver'

then ...

Such coding practices are perfectly expectable provided that the conditional values, age and city, never change. They become entirely unacceptable if a need for different values could be anticipated. A classic example of where this practice occurred that caused considerable heartache in the IT industry was the Y2K issue where dates were updated using only the last 2 digits of a four digit number because the first 2 digits were hard-coded to 19 i.e. 1998, 1999. All was well provided that the date did not advance to a time beyond the 1900’s since no one could be certain of what would happen when the millennia arrived (2000). A considerably amount of work (albeit boring) and money, approximately $200 billion, went into revising systems by way of software rewrites and computer chip replacements in order to thwart any detrimental outcomes. It is obvious how a simple change or an assumption can have sweeping consequences.

You may wonder what Y2K has to do with Business Rule Management Systems (BRMS). Well, what if we considered rules themselves to be hard-coded. If we were to write 100s of rules in Java, .NET or whatever language that only worked for a given scenario or assumption, would that not constitute hard-coded logic? By hard-coded, we obviously mean compiled. For example, if a credit card company has a variety of bonus campaigns, each with their own unique list of rules that may change within a week’s time, what would be the most effective way of writing software to deal with these responsibilities?

If you’re interested in building modern websites or applications which use ASP, XML, or mobile technology, you’ve heard of Visual Studio .NET.  It is one of the more popular suites of development tools available to aspiring programmers, as it consolidates several different tools and languages into the same development environment, which helps in turn to integrate this code across development languages.  Here are three important benefits to using the visual studio suite:

·         Use of Visual J# - This development tool is specifically oriented towards people who already are familiar with basic Java syntax, and is designed for use by those people to build apps or services which will then run on the Microsoft .NET Framework.  This is useful because it fully supports Microsoft Extensions, among other reasons.  Visual J# was developed completely independently by Microsoft.

·         Utility for Smart Devices – Another huge benefit of using visual studio .NET is the ability to immediately integrate your programming efforts with deployment across a variety of smart devices.  PDAs, smartphones, Pocket PCs, and any device which has a limited amount of resources all require a compact framework for the programming of applications it is designed to run.

·         XML Web Usage and Support – Because XML services aren’t married to any particular technology or programming language, they can be accessed by any system, and this broad-based utility has made the services increasingly popular.  Visual Studio .NET takes advantage of this by fully integrating with XML services, including the ability to create and edit them from scratch.

Checking to see if a file exists is a two step process in Python. Simply import the module shown below and invoke the isfile function:

import os.path
os.path.isfile(fname)