Let's take a sample class.
class Book:
def __init__(self, title, author):
self.title = title
self.author = author
book1 = Book(title="Right Ho, Jeeves", author="P.G. Wodehouse")
In Python you can access the attribute title of the class using the dot notation.
>>> book1.title
'P.G. Wodehouse'
If an attribute doesn't exist, Python throws an error:
>>> book1.series
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'Book' object has no attribute 'series'