CODEWITHSUNDEEP
pythonproperties
Ron
Ron

Reputation: 2019

@def vs @property, @foo.setter

I decided to give learning python a go today, going in the traditional "try random things until something works" way.

I started reading about classes, and then properties, and I tried to create some on my own. Most examples, and even examples from questions on this site, define properties like this:

class C(object):
    def __init__(self):
        self._x = None

    @property
    def x(self):
        """I'm the 'x' property."""
        return self._x

    @x.setter
    # etc. taken from the python tutorial

When I start typing "@pro" in my text editor and hit tab, it completes to this:

# ... Class stuff ...
@def foo():
    doc = "The foo property."
    def fget(self):
        return self._foo
    def fset(self, value):
    self._foo = value
foo = property(**foo())

Do these do the same thing, if they do, which one should I use (i.e. which is considered better practice)?

Upvotes: 2

Views: 1637

Answers (1)

rmunn
rmunn

Reputation: 36718

As has been mentioned, @def foo(): is invalid syntax and should be def foo():. With that one caveat, the two code samples you posted do pretty much the same thing. The @ operator takes a function-that-works-on-functions and applies it to the next defined function. In other words:

@property
def the_answer():
    return 42

is exactly the same as:

def the_answer():
    return 42
the_answer = property(the_answer)

But the @property way of writing this is easier to write, read, and understand, which is why it's considered better practice.

Upvotes: 3

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