Do you use the get/set pattern (in Python)?



Answers

In python, you can just access the attribute directly because it is public:

class MyClass(object):

    def __init__(self):
        self.my_attribute = 0  

my_object = MyClass()
my_object.my_attribute = 1 # etc.

If you want to do something on access or mutation of the attribute, you can use properties:

class MyClass(object):

    def __init__(self):
        self._my_attribute = 0

    @property
    def my_attribute(self):
        # Do something if you want
        return self._my_attribute

    @my_attribute.setter
    def my_attribute(self, value):
        # Do something if you want
        self._my_attribute = value

Crucially, the client code remains the same.

Question

Using get/set seems to be a common practice in Java (for various reasons), but I hardly see Python code that uses this.

Why do you use or avoid get/set methods in Python?




No, it's unpythonic. The generally accepted way is to use normal data attribute and replace the ones that need more complex get/set logic with properties.




Your observation is correct. This is not a normal style of Python programming. Attributes are all public, so you just access (get, set, delete) them as you would with attributes of any object that has them (not just classes or instances). It's easy to tell when Java programmers learn Python because their Python code looks like Java using Python syntax!

I definitely agree with all previous posters, especially @Maximiliano's link to Phillip's famous article and @Max's suggestion that anything more complex than the standard way of setting (and getting) class and instance attributes is to use Properties (or Descriptors to generalize even more) to customize the getting and setting of attributes! (This includes being able to add your own customized versions of private, protected, friend, or whatever policy you want if you desire something other than public.)

As an interesting demo, in Core Python Programming (chapter 13, section 13.16), I came up with an example of using descriptors to store attributes to disk instead of in memory!! Yes, it's an odd form of persistent storage, but it does show you an example of what is possible!

Here's another related post that you may find useful as well: Python: multiple properties, one setter/getter




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