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Trying to find examples of when decorators might be really beneficial, and when not so much. Sample code is appreciated.
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Example:2 - @staticmethod decorator- The @staticmethod is used to define a static method in the class. It is called by using the class name as well as instance of the class.
You'll use a decorator when you need to change the behavior of a function without modifying the function itself. A few good examples are when you want to add logging, test performance, perform caching, verify permissions, and so on. You can also use one when you need to run the same code on multiple functions.
A decorator in Python is a function that takes another function as its argument, and returns yet another function . Decorators can be extremely useful as they allow the extension of an existing function, without any modification to the original function source code.
Decorators are a very powerful and useful tool in Python since it allows programmers to modify the behaviour of a function or class. Decorators allow us to wrap another function in order to extend the behaviour of the wrapped function, without permanently modifying it.
Decorators are simple syntax for a specific way to call higher-order functions, so if you're focusing just on the syntax it's unlikely to make a great difference. IOW, wherever you can say
@mydecorator
def f(...):
# body of f
you could identically say
def f(...):
# body of f
f = mydecorator(f)
The decorator syntax's advantage is that it's a wee bit more concise (no repeating f three times;-) and that it comes before the def (or class, for class decorators) statement, thus immediately alerting the reader of the code. It's important, but it just can't be great!
The semantics of decorators (and, identically, of higher-order function calls that match this pattern, if there were no decorators;-). For example,
@classmethod
def f(cls, ...):
lets you make class methods (very useful esp. for alternate constructors), and
@property
def foo(self, ...):
lets you make read-only properties (with other related decorators in 2.6 for non-read-only properties;-), which are extremely useful even when not used (since they save you from writing lot of dumb "boilerplate" accessors for what are essentially attributes... just because access to the attribute might require triggering some computation in the future!-).
Beyond the ones built into Python, your own decorators can be just as important -- depending on what your application is, of course. In general, they make it easy to refactor some part of the code (which would otherwise have to be duplicated in many functions and classes [[or you might have to resort to metaclasses for the class case, but those are richer and more complicated to use correctly]]) into the decorator. Therefore, they help you avoid repetitious, boilerplatey code -- and since DRY, "Don't Repeat Yourself", is a core principle of software development, any help you can get towards it should be heartily welcome.
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