slots | What is the Usage of __slots__?

In this post, we will get to know more about the Usage of __ slots__ in Python where slot is a class variable that has flexibility as it allows us to explicitly declare the attributes that have an instance as the class can have, which leads for reducing the memory footprint and improving performance. 



As we need to know that by default, in Python classes that we use a dictionary to store their instance attributes. This dictionary allows you to dynamically add new attributes to instances at runtime. However, the use of dictionaries for attribute storage has some overhead, both in terms of memory usage and access time.

When you define the slot variable in your class, you are telling Python to use a more efficient mechanism for storing attributes. Instead of using a dictionary, Python will use a tuple to store the attributes. This makes the instance smaller in memory and faster to access.

And for the same, we have given an example of a pseudo -code for execution and implemented it on our machine below.

class MyClass:
    __slot__ = ('attribute1', 'attribute2')
    def __init__( self, attribute1, attribute2):
        self. attribute1 = attribute1
        self. attribute2 = attribute2

In the above given example, of slot uses for to specify that instances of my class can only have attribute 1 and attribute 2 If you try to set any other attribute on an instance of this class, you will get an Attribute error.

It’s important to note that using Slot is an optimization technique, and should only be used when you know that you have a large number of instances of a class and you need to reduce memory usage. In most cases, the default attribute storage mechanism provided by Python is sufficient.

Here are some more details about slot which might help you in getting it better and understand things better.

  1. In addition to attribute names, you can also include other class variables in the ” __slot__ ” tuple. These will be treated as class-level attributes and will be shared among all instances of the class.
  2. Moreover If we want to subclass a class that defines “__slot__ “the subclass will have its own “__slot__ ” variable, which will override the one defined in the parent class. If you need to add additional attributes to the subclass, you can define a new “__slot__ ” variable that includes the names of both the parent class’s attributes and the new attributes.
  3. Here also if we define a “__slot__ ” attribute in your class, it will override the use of “__slot__ ” and allow instances to have arbitrary attributes.
  4. At last, we need to keep in mind during using “__slot__ ” you cannot use some built-in features of Python, such as multiple inheritances or dynamic attribute access.



To learn more about the Usage of __slots__ visit:  by stack overflow.

To learn more about solutions to different problems and tutorials for the concepts we need to know to work on programming along with different ways to solve any generally asked problems: How To Pass-Variables From A Java & Python Client To A Linux/Ubuntu Server Which Is Running C?.

Leave a Comment

%d bloggers like this: