This is in Python! 8.28 Develop a class Textfile that provides methods to analyze a text file. The class
Textfile will support a constructor that takes as input a file name (as a string) and instantiates
a Textfile object associated with the corresponding text file. The Textfile class should support methods nchars(), nwords(), and nlines() that return the number
of characters, words, and lines, respectively, in the associated text file. The class should
also support methods read() and readlines() that return the content of the text file as a
string or as a list of lines, respectively, just as we would expect for file objects.
Finally, the class should support method grep() that takes a target string as input and
searches for lines in the text file that contain the target string. The method returns the lines
in the file containing the target string; in addition, the method should print the line number,
where line numbering starts with 0.
>>> t = Textfile('raven. txt') File: raven. txt
>>> t. nchars()
6299
>>> t. nwords()
1125
>>> t. nlines()
126
>>> print(t. read())
Once upon a midnight dreary, while I pondered weak and weary,
...
Shall be lifted - nevermore!
>>> t. grep('nevermore')
75: Of `Never-nevermore.`
89: She shall press, ah, nevermore!
124: Shall be lifted - nevermore!

8.29 Add method words() to class Textfile from Problem 8.28. It takes no input and
returns a list, without duplicates, of words in the file.

8.30 Add method occurrences() to class Textfile from Problem 8.28. It takes no input
and returns a dictionary mapping each word in the file (the key) to the number of times it
occurs in the file (the value).

8.31 Add method average() to class Textfile from Problem 8.28. It takes no input and
returns, in a tuple object, (1) the average number of words per sentence in the file, (2) the
number of words in the sentence with the most words, and (3) the number of words in the
sentence with the fewest words. You may assume that the symbols delimiting a sentence
are in '!?.'.

8.41 Consider the class tree hierarchy:
Animal
Mammal
Cat Dog Primate
Hacker
Implement six classes to model this taxonomy with Python inheritance. In class Animal,
implement method speak() that will be inherited by the descendant classes of Animal as
is. Complete the implementation of the six classes so they exhibit this behavior:
>>> garfield = Cat()
>>> garfield. speak()
Meeow
>>> dude = Hacker()
>>> dude. speak( )
Hello world!