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)

No industry is as global as software development.  Pervasive networking means that software developers can, and do, work from anywhere. This has led many businesses to hiring development subcontractors in other countries, aiming to find good development talent at lower prices, or with fewer hassles on entry into the US.

While this is an ongoing and dynamic equilibrium, there are compelling reasons for doing software development in the United States, or using a hybrid model where some parts of the task are parceled out to foreign contractors and some are handled locally.

Development Methodologies

The primary reason for developing software overseas is cost reduction. The primary argument against overseas software development is slower development cycles. When software still used the "waterfall" industrial process for project management (where everything is budgeted in terms of time at the beginning of the project), offshoring was quite compelling. As more companies emulate Google and Facebook's process of "release early, update often, and refine from user feedback," an increasing premium has been put on software teams that are small enough to be agile (indeed, the development process is called Agile Development), and centralized enough, in terms of time zones, that collaborators can work together. This has made both Google and Facebook leaders in US-based software development, though they both still maintain teams of developers in other countries tasked with specific projects.

Localization For Americans

The United States is still one of the major markets for software development, and projects aimed at American customers needs to meet cultural norms. This applies to any country, not just the U.S. This puts a premium on software developers who aren't just fluent in English, but native speakers, and who understand American culture. While it's possible (and even likely) to make server-side software, and management utilities that can get by with terse, fractured English, anything that's enterprise-facing or consumer-facing requires more work on polish and presentation than is practical using outsourced developers. There is a reason why the leaders in software User Interface development are all US-based companies, and that's because consumer-focused design is still an overwhelming US advantage.

Ongoing Concerns

The primary concern for American software development is talent production. The US secondary education system produces a much smaller percentage of students with a solid math and engineering background, and while US universities lead the world in their computer science and engineering curricula, slightly under half of all of those graduates are from foreign countries, because American students don't take the course loads needed to succeed in them. Software development companies in the United States are deeply concerned about getting enough engineers and programmers out of the US university system. Some, such as Google, are trying to get programmers hooked on logical problem solving at a young age, with the Summer of Code programs. Others, like Microsoft, offer scholarships for computer science degrees.

Overall, the changes in project management methodologies mean that the US is the current leader in software development, and so long as the primary market for software remains English and American-centric, that's going to remain true. That trend is far from guaranteed, and in the world of software, things can change quickly.

With stiff penalties for being caught and the whiff of secretive underground or even nefarious acts, computer hacking can be seen as a somewhat dubious pursuit. Not all hackers operate with the motive of emptying your Paypal account, however; there are many hackers who utilize their skills to aid companies in locating security flaws ("penetration testing") or engage in hacking with the goal of becoming cyber-freedom-fighters that champion simple human freedoms, such as the right to free speech.

Computer hacking is as much an art as it is a skill. At its simplest distillation, hacking is the systematic search for chinks in programming armor. While advanced problem-solving, intuition and sophisticated understanding of programming languages are a distinct advantage, there does exist a number of push-button programs that computing wizards have written allowing those less sophisticated in the art of hacking to break into remote computers in a variety of ways. Because of this new ubiquity, today's hackers no longer need to be a programming Wunderkind; they simply need to know where to download software and be able to turn on a computer. It really is that simple and the implications can be disturbing.

Phishing, Push-Button Programs and Brute Force Tactics

There's no need to crack a company's firewall if you have direct physical access to their computers. One aspect of hacking is the impersonation of an employee or service worker with the goal of gaining access to a company's database, where the hacker can then unleash whatever havoc he or she has planned into the system. Another is to engage in simple phishing techniques, such as impersonating an employee who forgot their password and needs help logging into the system.

Because such impersonations often fail thanks to companies becoming more security-conscious, taking over operations of a computer remotely is often the preferred method of gaining access. Such attempts can be facilitated in a variety of ways. One is the brute-force method, in which a program such as SQLmap, Nmap or Burpsuite is used; running one of these programs is analogous to trying every doorknob in a neighborhood to see which house is unlocked. Using a variety of different parameters, these programs can find access to a vulnerable computer or network in less than a minute.

Hackers can also attempt to gain access with a program like Metasploit. With literally a few clicks of a mouse, access to a remote and vulnerable computer can be achieved by a relative newbie. With a related hacking aid, called Meterpreter, a backdoor is created that allows access into an operating system. It does not install itself onto the remote computer, running instead using the computer's memory; in fact, Meterpreter can hide itself inside the operations of a perfectly valid program, so it cannot be detected even by sophisticated programmers. Once engaged, it allows a remote user carte blanche access to the system in question.

Where to Learn the Art of Hacking

Of course, for those who wish to learn the actual skills rather than download someone else's hack, there are a number of practice sites that pose an increasingly difficult set of challenges intended to train neophytes in the art of hacking. For example, Hack This Site starts beginners with the goal of cracking simple flaws in coding scripts or software such as HTML, Unix, Javascript and Apache. Their structured series of tests increase in complexity, incorporating real-word scenarios and even old-fashioned "phone phreaking" challenges that recall the bygone golden age of hacking skills displayed by Matthew Broderick in "WarGames."

Using just these simple tools and free practice sites, beginners have a powerful array of hacking resources just a simple mouse click away.

Different programming languages gain popularity for different features.  Java tutorials have proven particular popular over a long period of time, thanks to a diverse group of strengths inherent to the language itself.  Let’s examine some of the basic elements of Java, and find out what it is both powerful and popular:

·         WORA – Write Once Run Anywhere is a programming ideal that has never been effectively achieved.  The goal is to be able to write code a single time, and have it deploy in the same way across multiple platforms.  Although it is still an ideal, proper Java tutorials exist that demonstrate how we are moving closer to success.

·         Object-Oriented – This programming philosophy designates that there is no coding that takes place outside established class definitions.  A large class library is also available right within the core language pack.

·         Compiler plus Interpreter – Once you have written your code, you can compile it into bytecodes which are then fed into a JVM, or Java virtual machine.  You can then follow popular Java tutorials to see how you can extensively debug your code using this functionality.