Description
1. Introduction
In this assignment, we are going to read the complete works of William Shakespeare and write
an essay about how Shakespeare chooses his words.
Just kidding 🙂 But this is not far from the truth. In fact, we are going to write Python code to
read the complete works of William Shakespeare and then report the word frequencies of the
words used in his works.
2. Objectives
The purpose of this assignment is to give you experience in:
• Understanding when to use dictionary and how dictionary is implemented.
• Implementing and using the basic operations of a mapping (dictionary).
• Learn how to handle a file and practice some string operations.
• Learn what to do when we need to sort a dictionary according to the values.
Note: Before you start, if you are not familiar with content of mappings and hash tables, it is
recommended you read the class notes first and do the code for thought #13, #14, and #15.
3. Background
3.1. The Complete Works of William Shakespeare
The text file that has the complete works of William Shakespeare is provided with the skeleton
code. This text file has a special format. That is, every word or symbol is followed by a space.
This makes the job of splitting words easier. This text file has all the works of Shakespeare, and
it is very long. The size of the text file is about 4.5 Mbytes. The total number of lines is 129,107,
the total number of words and symbols is 980,637, and the total number of characters is
4,538,523.
Here is the beginning of the text file:
A MIDSUMMER-NIGHT’S DREAM
Now , fair Hippolyta , our nuptial hour
Draws on apace : four happy days bring in
Another moon ; but O ! methinks how slow
This old moon wanes ; she lingers my desires ,
Like to a step dame , or a dowager
Long withering out a young man’s revenue .
Four days will quickly steep themselves in night ;
Four nights will quickly dream away the time ;
And then the moon , like to a silver bow
New-bent in heaven , shall behold the night
Of our solemnities .
Go , Philostrate ,
Stir up the Athenian youth to merriments ;
Awake the pert and nimble spirit of mirth ;
Turn melancholy forth to funerals ;
The pale companion is not for our pomp .
Hippolyta , I woo’d thee with my sword ,
And won thy love doing thee injuries ;
But I will wed thee in another key ,
With pomp , with triumph , and with revelling .
We will read this text file and count the number of times each of the words and symbols appear
in the text file.
4. Assignment
In the skeleton zip file, you will find a skeleton for your .py file named shakespeare.py. All you
need to do is to complete the skeleton code based on the instructions and submit it to the
Mimir system.
4.1. Solving the problem using dictionary
We first solve the problem using dictionary. The symbol code is included in the skeleton code.
import operator
import time
f = open(‘shakespeare.txt’, ‘r’)
data = f.read()
f.close()
data = data.split()
start = time.time()
d = {}
for i in range(len(data)):
key = data[i].lower()
if key in d:
d[key] += 1
else:
d[key] = 0
sorted_d = sorted(d.items(), key=operator.itemgetter(1), reverse = True)
k = 0
count = 0
while count < 20:
if sorted_d[k][0] not in {“‘”, “:”, “!”, “.”, “,”, “;”, “?”}:
print(count + 1, sorted_d[k])
count += 1
k += 1
end = time.time()
print(end – start)
In the above code, we first read the text file into a string and split the string into symbols and
words. And then we loop through the list of symbols and words and use a dictionary to count
the number of times these symbols and words appeared in the list. After that, we sorted
function to sort the dictionary according to the values and save the result into a list. Last, we
print out the top 20 frequently used words and their corresponding frequencies.
4.1. Solving the problem using HashMapping
Your job now is to use the code from code for thought #14 and code for thought #15 to
implement class HashMapping and use this class to replace the dictionary above and repeat the
above operations and obtain the same results. Note you need to implement class Entry,
Mapping, ListMapping and HashMapping.
Below is a screenshot of my results. Using dictionary, we get the job done in 2 seconds. Using
HashMapping, it is done around 9 seconds.
5. Submit your work to Mimir
Submit your code to Mimir after you complete your code. Mimir will automatically check the
output of your code and grade your submission. You can submit your code to Mimir up to 30
times to refresh your existing score before the submission deadline. Before you submit your
code, comment out all the code outside of the class Entry, Mapping, ListMapping and
HashMapping.
6. Due date
This lab assignment is worth 4 points in the final grade. It will be due by 11:59pm on November
13th, . A penalty of 10% per day will be deducted from your grade, starting at 12:00am.
