Python is an incredibly versatile language that has a wide range of capabilities. One of these unique features is the concept of decorators, which often baffles beginner and intermediate developers. In this blog post, we will shed some light on the mystery of decorators and what they are used for.
### What are Decorators?
Decorators are a significant part of Python. They are a unique feature that allows programmers to modify the behavior of a function or class. Decorators are usually called before the definition of a function you intend to decorate.
Here is an example of a simple decorator:
```python
def simple_decorator(func):
def wrapper():
print("Action before function.")
func()
print("Action after function.")
return wrapper
@simple_decorator
def greet():
print("Hello!")
When you run greet(), it would not just print "Hello!", it would also print "Action before function." before the greeting and "Action after function." after, thanks to the decorator.
When you call a function that is decorated by @simple_decorator, Python will pass that function to the decorator. Inside the decorator, we define a wrapper function that wraps the actions we want to execute before and after the decorated function runs.
The reason the extra actions don't execute immediately when you define the function (and instead only run when you call the function) is because of how decorators work with timing. When you use @simple_decorator, Python calls simple_decorator(greet) right when you define greet(). However, Python doesn’t call the wrapper() function until you call greet().
greet() # Output: # Action before function. # Hello! # Action after function.
Python's decorators allow you to amplify your functions, modifying their behavior with a significant degree of control. They might seem a little complex at first glance, but with enough practice, they'll become a vital tool in your Python toolbox.
In abstract terms, decorators work by receiving a function and returning a new function that extends the work of the original function. This concept, while abstract, is one of the key aspects of Python and indeed, many other programming languages.
Happy coding!