The decorator pattern is a design pattern that allows you to wrap an object such that it will appear to execute a given behavior in many different ways at different points in program execution. This is especially useful when you want an object to have different behaviors at but are unable to mutate the object. The decorator pattern is a useful way to implement dynamic behavior without needing an extended inheritance-based class hierarchy. To use the decorator pattern you need four elements: a component interface; a concrete component; a decorator abstraction; and, a concrete decorator. The interface sets the contract for both component and decorator behavior, the decorator abstraction contains a pointer to some concrete component, and the concrete decorators wrap a concrete component and override behavior if desired.
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.
Peter Heller is the best-selling author of The Dog Stars. He holds an MFA from the Iowa Writers’ Workshop in both fiction and poetry. An award-winning adventure writer and a longtime contributor to NPR, Heller is a contributing editor at Outside magazine, Men’s Journal, and National Geographic Adventure, and a regular contributor to Bloomberg Businessweek. He is also the author of several nonfiction books, including Kook, The Whale Warriors, and Hell or High Water: Surviving Tibet’s Tsangpo River. He lives in Denver, Colorado.
Portrait paintings are representations of a person, in which the face and its expression is predominant. The intent is to display the likeness, personality, and even the mood of the person. The art of the portrait flourished in Ancient Greek and especially Roman sculpture, where sitters demanded individualized and realistic portraits, even unflattering ones. One of the best-known portraits in the Western world is Leonardo da Vinci's painting titled Mona Lisa, which is thought to be a portrait of Lisa Gherardini, the wife of Francesco del Giocondo.
Broadgate Campus, Liverpool Street WEDNESDAY TO SUNDAY HOURS ONLY 2-11pm (Weds - Fri) 6am - 3pm (Sat & Sun) JPC prides itself in being a family run business which aspires to promote these family values throughout the business structure. In joining with us you are open to receive many work based benefits including full induction including BICs training, continued training and development opportunities throughout career, top 10% open to consideration for promotion to senior positions, uniform provided and recognition for outstanding performance at work. Our business is continually growing and evolving so why not join and grow with us! Responsibilities: · Collection and Compaction of Recycling and General waste · All refuse to be correctly segregated, with all salvageable recycling extricated and compacted appropriately. · Accurate Weighing and recording of all waste on the Weightron scales. · Safe use of the Tow Trucks throughout the Loading Bay. · Strict adherence to Risk assessments and Method statements. · Follow the schedule of works, completi
By downloading this trial product, you agree to receive marketing communications from us and/or our suppliers. You may opt-out of receiving such future emails by clicking the unsubscribe link in any email you receive, or by signing into your Corel account through our website using your email address and password, and clicking on Manage Your Communication Preferences.