Python creates instance fields automatically, so they do not need to be declared, but good style is to always set any
instance fields an object will have in its constructor. Unlike in Java, where this.
before a field or
method name can be omitted if there is no ambiguity, the self.
in Python is always mandatory; otherwise
Python will create a local variable instead. For example:
class Book(object):
def __init__(self, title):
self.title = title
self.checked_out = False
Fill in the placeholders so that the actual outputs match the expected outputs.