Classes are a useful way of storing related data items (in much the same way that a dictionary can store key-value pairs). The code in this exercise implements a class for holding name and email address information. The functionextract_namesoperates on a list ofContactobjects to extract the names and return them insortedorder.

Hint:Iterate through objects in theaddress_bookand append thenamemember variable associated with each object to a running list of names. Don't forget to sort the names before returning from the function.

Code:

class Contact:

"""Encapsulates an email contact."""

def __init__(self, name, email):

self.name = name

self.email = email

# DO NOT MODIFY CODE ABOVE THIS LINE

def extract_names(address_book):

"""Return a sorted list of all names in an address book,

implemented as a list of Contact objects."""

# TODO: implement this function and replace the return statement

return None

# DO NOT MODIFY CODE BELOW THIS LINE

addr_book = []

addr_book.append(Contact("Mickey Mouse", "..y@disneyland.com"))

addr_book.append(Contact("Minnie Mouse", "..e@disneyland.com"))

addr_book.append(Contact("Goofy", "..y@disneyland.com"))

addr_book.append(Contact("Pluto", "..o@disneyland.com"))

addr_book.append(Contact("Winnie the Pooh", "..r@disneyland.com"))

print(" ".join(extract_names(addr_book)))