How to define attributes of a class in Python?

Attributes of a class

Everything, almost everything in Python is an object. Every object has attributes and methods. Thus attributes are very fundamental in Python. A class is a construct which is a collection of similar objects. A class also has attributes. There will be a difference between the class attributes and instance attributes. The class attributes are shared by the instances of the class but it not true vice versa.

Example

We can get a list of the attributes of an object using the built-in “dir” function. For example −

>>> s = 'abc'
>>> len(dir(s))
71
>>> dir(s)[:5]
['__add__', '__class__', '__contains__', '__delattr__', '__doc__']
>>> i = 123
>>> len(dir(i))
64
>>> dir(i)[:5]
['__abs__', '__add__', '__and__', '__class__', '__cmp__']
>>> t = (1,2,3)
>>> len(dir(t))
32
>>> dir(t)[:5]
['__add__', '__class__', '__contains__', '__delattr__', '__doc__']

As we can see, even the basic data types in Python have many attributes. We can see the first five attributes by limiting the output from “dir”;