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)

Computers. They’re a part of our everyday lives. Most of us couldn’t imagine living a day without them. We use them for school, work, and fun and use them to stay connected to those we love and care about. Since the invention of the web cam, millions of us use webcams to communicate with loved-ones and business contacts far away.

Web camera use has leveled the playing field for business entrepreneurs and given teenagers a fun way to chat with friends. However, solid citizens aren’t the only ones who make use of this popular modern technology. Recently, there have been reports of criminals using a type of webcam spy hack to insert themselves unseen into the living rooms and bedrooms of millions of unsuspecting users.

The Webcam Spy Hack

The most popular way criminals gain access to your webcam is through innocent-looking emails. You may receive an e-card from someone in your contacts list. When you click on it, you’re directed to another website to view the e-card. While you’re listening to music and watching animated puppies scroll across the screen, a Trojan horse is silently installed into your computer’s hard drive.

I’ll get straight to the point.  Why should companies invest more in management training?  Here are 10 simple reasons.

1) An employee’s relationship with his or her direct manager is the most important single factor in employee engagement.

2) Engaged employees are happier and more productive.  Disengaged employees are frustrated and more disruptive.

3) Because there’s no widely agreed-on skillset for management (good managers come in all shapes and sizes), there’s an assumption everyone knows how to do it.  This is akin to someone who’s never driven before being given keys to a car and told: “Drive.”  (Many many years ago, this is how I first learned to manage.  I blundered my way through it.  Trial and error.  It wasn’t pretty.)

It is said that spoken languages shape thoughts by their inclusion and exclusion of concepts, and by structuring them in different ways. Similarly, programming languages shape solutions by making some tasks easier and others less aesthetic. Using F# instead of C# reshapes software projects in ways that prefer certain development styles and outcomes, changing what is possible and how it is achieved.

F# is a functional language from Microsoft's research division. While once relegated to the land of impractical academia, the principles espoused by functional programming are beginning to garner mainstream appeal.

As its name implies, functions are first-class citizens in functional programming. Blocks of code can be stored in variables, passed to other functions, and infinitely composed into higher-order functions, encouraging cleaner abstractions and easier testing. While it has long been possible to store and pass code, F#'s clean syntax for higher-order functions encourages them as a solution to any problem seeking an abstraction.

F# also encourages immutability. Instead of maintaining state in variables, functional programming with F# models programs as a series of functions converting inputs to outputs. While this introduces complications for those used to imperative styles, the benefits of immutability mesh well with many current developments best practices.

For instance, if functions are pure, handling only immutable data and exhibiting no side effects, then testing is vastly simplified. It is very easy to test that a specific block of code always returns the same value given the same inputs, and by modeling code as a series of immutable functions, it becomes possible to gain a deep and highly precise set of guarantees that software will behave exactly as written.

Further, if execution flow is exclusively a matter of routing function inputs to outputs, then concurrency is vastly simplified. By shifting away from mutable state to immutable functions, the need for locks and semaphores is vastly reduced if not entirely eliminated, and multi-processor development is almost effortless in many cases.

Type inference is another powerful feature of many functional languages. It is often unnecessary to specify argument and return types, since any modern compiler can infer them automatically. F# brings this feature to most areas of the language, making F# feel less like a statically-typed language and more like Ruby or Python. F# also eliminates noise like braces, explicit returns, and other bits of ceremony that make languages feel cumbersome.

Functional programming with F# makes it possible to write concise, easily testable code that is simpler to parallelize and reason about. However, strict functional styles often require imperative developers to learn new ways of thinking that are not as intuitive. Fortunately, F# makes it possible to incrementally change habits over time. Thanks to its hybrid object-oriented and functional nature, and its clean interoperability with the .net platform, F# developers can gradually shift to a more functional mindset while still using the algorithms and libraries with which they are most familiar.

Related F# Resources:

F# Programming Essentials Training