This difference becomes most important when there are several independent ways of extending functionality. In some object-oriented programming languages, classes cannot be created at runtime, and it is typically not possible to predict, at design time, what combinations of extensions will be needed. This would mean that a new class would have to be made for every possible combination. By contrast, decorators are objects, created at runtime, and can be combined on a per-use basis. The I/O Streams implementations of both Java and the .NET Framework incorporate the decorator pattern.
In general, functions in Python may also have side effects rather than just turning an input into an output. The print() function is a basic example of this: it returns None while having the side effect of outputting something to the console. However, to understand decorators, it is enough to think about functions as something that turns given arguments into a value.
In object-oriented programming, the decorator pattern is a design pattern that allows behavior to be added to an individual object, dynamically, without affecting the behavior of other objects from the same class. The decorator pattern is often useful for adhering to the Single Responsibility Principle, as it allows functionality to be divided between classes with unique areas of concern. The decorator pattern is structurally nearly identical to the chain of responsibility pattern, the difference being that in a chain of responsibility, exactly one of the classes handles the request, while for the decorator, all classes handle the request.
As an example, consider a window in a windowing system. To allow scrolling of the window's contents, one may wish to add horizontal or vertical scrollbars to it, as appropriate. Assume windows are represented by instances of the Window interface, and assume this class has no functionality for adding scrollbars. One could create a subclass ScrollingWindow that provides them, or create a ScrollingWindowDecorator that adds this functionality to existing Window objects. At this point, either solution would be fine.
Modifying classes in this fashion is also possible, though the benefits are not as immediately apparent. Almost certainly, anything which could be done with class decorators could be done using metaclasses, but using metaclasses is sufficiently obscure that there is some attraction to having an easier way to make simple modifications to classes. For Python 2.4, only function/method decorators are being added.
After having shot a man in a Santa Fe bar, the famous artist Jim Stegner served his time and has since struggled to manage the dark impulses that sometimes overtake him. Now he lives a quiet life. . . until the day that he comes across a hunting guide beating a small horse, and a brutal act of new violence rips his quiet life right open. Pursued by men dead set on retribution, Jim is left with no choice but to return to New Mexico and the high-profile life he left behind, where he’ll reckon with past deeds and the dark shadows in his own heart.
Michael Barker Painters And Decorators have many satisfied and returning customers because we provide the best and most comprehensive painting and decorating services in and around crook, with a friendly service from start to completion, and a time served and highly skilled team, you can rest assured that you are getting both excellent value for money and a personal service at each and every job we attend.
Painters apply paint, stain, varnish and other finishes to buildings and other structures. They select the right paint or finish for the surface to be covered, taking into account durability, ease of handling, method of application and customer's wishes. Painters first prepare the surfaces to be covered, so that the paint will adhere properly. This may require removing the old coat of paint by stripping, sanding, wire brushing, burning, scraping, or water and abrasive blasting. Painters also wash walls and trim to remove dirt and grease, fill nail holes and cracks, sandpaper rough spots and brush off dust. On new surfaces, they apply a primer or sealer to prepare the surface for the finish coat. Painters also mix paints and match colors, relying on knowledge of paint composition and color harmony. They also cover walls and ceilings with decorative wall coverings made of paper, vinyl or fabric.
Average Americans work well into their 60s, so workers might as well have a job that’s enjoyable and a career that's fulfilling. A job with a low stress level, good work-life balance and solid prospects to improve, get promoted and earn a higher salary would make many employees happy. Here's how Painters job satisfaction is rated in terms of upward mobility, stress level and flexibility.
... the keyword starting the line that heads a block draws a lot of attention to it. This is true for "if", "while", "for", "try", "def" and "class". But the "using" keyword (or any other keyword in its place) doesn't deserve that attention; the emphasis should be on the decorator or decorators inside the suite, since those are the important modifiers to the function definition that follows. ...
I have been a Raoul Dufy fan for over ten years, searching out his paintings throughout museums in the US. I've been looking for information about him but come up empty. Found this dvd on Amazon. It was great. The documentary had terrific interviews and gorgeous images of his paintings. Even more it gave me a baseline for who is was and the scope of his work.
The Crowne Plaza London Kings Cross has recently completed its exciting journey to emerge as the newest Crowne Plaza hotel in London following a multi-million pound refurbishment and re-branding from Holiday Inn. Our hotel has 429 newly designed bedrooms, the first franchised Belgo Restaurant and the Bloom Bar & Kitchen, which opened a few months ago. The hotel also has 6 state of the art Meeting & Event spaces, a Club Lounge and a Leisure Club. A new opportunity has arisen for the position of Maintenance Shift Engineer. This position would suit a multi-skilled, hands-on, motivated and hard-working individual looking to develop. A person should be adaptable, flexible and able to work both independently and with the team. Experience within the hotel industry and Maintenance/Engineering is desirable but not critically essential. Ideally the candidate will have electrical, mechanical, carpentry, plumbing and decorating/tiling skills and a reasonable working knowledge of stringent PPM of automated plant equipment and general building maintenance. A good level of English is essential. Key responsibilities -Report to the Maintenance Supervisor before your shift starts to go through your daily tasks. -Promptly and efficiently attends and inspects all maintenance requests, defects or Health & Safety matters su
Rhythm is important in painting as it is in music. If one defines rhythm as "a pause incorporated into a sequence", then there can be rhythm in paintings. These pauses allow creative force to intervene and add new creations—form, melody, coloration. The distribution of form, or any kind of information is of crucial importance in the given work of art, and it directly affects the aesthetic value of that work. This is because the aesthetical value is functionality dependent, i.e. the freedom (of movement) of perception is perceived as beauty. Free flow of energy, in art as well as in other forms of "techne", directly contributes to the aesthetical value.