The discussion continued on and off on python-dev from February 2002 through July 2004. Hundreds and hundreds of posts were made, with people proposing many possible syntax variations. Guido took a list of proposals to EuroPython 2004 [7], where a discussion took place. Subsequent to this, he decided that we'd have the Java-style [10] @decorator syntax, and this appeared for the first time in 2.4a2. Barry Warsaw named this the 'pie-decorator' syntax, in honor of the Pie-thon Parrot shootout which occurred around the same time as the decorator syntax, and because the @ looks a little like a pie. Guido outlined his case [8] on Python-dev, including this piece [9] on some of the (many) rejected forms.
Decorator Abstractions: Our decorator abstraction takes the form of the abstract MessageDecorator class, which also implements IMessage. The MessageDecorator class has a constructor that accepts an IMessage object as a parameter and then assigns it to a private variable. For its part, MessageDecorator doesn’t have any special behaviors and simply delegates GetMessage and PrintMessage calls to whichever IMessage object was injected into it.
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.
This code works for our purposes but it’s not exactly dynamic. If we wanted our initial simpleMsg object to sometimes act excited and sometimes quizzical, we could only do so by instantiating entirely new objects from the relevant subclass. Moreover, the ExcitedAndQuizzicalMessage is really just a combination of ExcitedMessage and QuizzicalMessage and probably shouldn’t have its own class. To fix these problems, let’s now return to the decorator pattern and see how it might help us.

Pastel is a painting medium in the form of a stick, consisting of pure powdered pigment and a binder.[19] The pigments used in pastels are the same as those used to produce all colored art media, including oil paints; the binder is of a neutral hue and low saturation. The color effect of pastels is closer to the natural dry pigments than that of any other process.[20] Because the surface of a pastel painting is fragile and easily smudged, its preservation requires protective measures such as framing under glass; it may also be sprayed with a fixative. Nonetheless, when made with permanent pigments and properly cared for, a pastel painting may endure unchanged for centuries. Pastels are not susceptible, as are paintings made with a fluid medium, to the cracking and discoloration that result from changes in the color, opacity, or dimensions of the medium as it dries.
Thanks to enhanced support for multi-core processors and CPUs that use AVX2 extensions and extensive code optimizations, this is the fastest version of Painter yet. A huge selection of brushes are noticeably faster — some as much as twice as fast. You can also take advantage of faster document rendering when zooming, panning and rotating — up to 50% faster.
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