Author Dusty Phillips Reviewers

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 135 
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Going one step further, we can specify a setter function for the new property
as follows:
class Foo:
@property
def foo(self):
return self._foo
@foo.setter
def foo(self, value):
self._foo = value
This syntax looks pretty odd, although the intent is obvious. First, we decorate the 
foo
method as a getter. Then, we decorate a second method with exactly the same 
name by applying the 
setter
attribute of the originally decorated 
foo
method! The 
property
function returns an object; this object always comes with its own 
setter
attribute, which can then be applied as a decorator to other functions. Using the same 
name for the get and set methods is not required, but it does help group the multiple 
methods that access one property together.
We can also specify a deletion function with 
@foo.deleter
. We cannot specify a 
docstring using 
property
decorators, so we need to rely on the property copying
the docstring from the initial getter method.
Here's our previous 
Silly
class rewritten to use 
property
as a decorator:
class Silly:
@property
def silly(self):
"This is a silly property"
print("You are getting silly")
return self._silly
@silly.setter
def silly(self, value):
print("You are making silly {}".format(value))
self._silly = value
@silly.deleter
def silly(self):
print("Whoah, you killed silly!")
del self._silly
This class operates 
exactly
the same as our earlier version, including the help text. 
You can use whichever syntax you feel is more readable and elegant.
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When to Use Object-oriented Programming