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

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Do you use get and set in Python?

Getters and Setters in python are often used when: We use getters & setters to add validation logic around getting and setting a value. To avoid direct access of a class field i.e. private variables cannot be accessed directly or modified by external user.

When to use Get set methods?

Getters and setters are used to protect your data, particularly when creating classes. For each instance variable, a getter method returns its value while a setter method sets or updates its value. Given this, getters and setters are also known as accessors and mutators, respectively.

What is the use of set and get?

The get method returns the value of the variable name . The set method assigns a value to the name variable. The value keyword represents the value we assign to the property.

What are get and set in Python OOPs?

As the name suggests, getters are the methods which help access the private attributes or get the value of the private attributes and setters are the methods which help change or set the value of private attributes.


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

class MyClass:

    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:

    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.


Cool link: Python is not Java :)

In Java, you have to use getters and setters because using public fields gives you no opportunity to go back and change your mind later to using getters and setters. So in Java, you might as well get the chore out of the way up front. In Python, this is silly, because you can start with a normal attribute and change your mind at any time, without affecting any clients of the class. So, don't write getters and setters.


Here is what Guido van Rossum says about that in Masterminds of Programming

What do you mean by "fighting the language"?

Guido: That usually means that they're trying to continue their habits that worked well with a different language.

[...] People will turn everything into a class, and turn every access into an accessor method,
where that is really not a wise thing to do in Python; you'll have more verbose code that is
harder to debug and runs a lot slower. You know the expression "You can write FORTRAN in any language?" You can write Java in any language, too.


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.


The short answer to your question is no, you should use properties when needed. Ryan Tamyoko provides the long answer in his article Getters/Setters/Fuxors

The basic value to take away from all this is that you want to strive to make sure every single line of code has some value or meaning to the programmer. Programming languages are for humans, not machines. If you have code that looks like it doesn’t do anything useful, is hard to read, or seems tedious, then chances are good that Python has some language feature that will let you remove it.


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