IT 117: Intermediate Scripting

IT 117: Intermediate Scripting
Homework 5

Due
What You Need to Do
Setup On Your Machine
Specification
Functions
Test Code
Output
Suggestions
Testing on Your Machine
Copy the Script to Unix
Testing the Script on Unix (Optional)

Due

Sunday, March 2nd at 11:59 PM

What You Need to Do

Create the script hw5.py
Make sure it obeys the rules in Rules for Homework Scripts
Make sure the script has a hashbang line and is executable
Move it to an an hw5 directory on pe15.cs.umb.edu

Setup On Your Machine

Open a text editor.
I would suggest the text editor built into the program IDLE.
Save the file as hw5.py
Copy the files gettysburg.txt and gettysburg_hay.txt from /home/ghoffman/course_files/it117_files.
Use FileZilla to do this.

Specification

This script compares the words found in two files
It reads each file and creates a set of words found in the file
Creates difference sets of the words found in one file but not the other
Prints the two difference sets
The script must contain 4 functions
- open_file_read
- word_set_create
- set_difference
- word_set_print

Functions

open_file_read

Header
```
def open_file_read(filename):
```
This function should create a file object for reading
If the file object cannot be created it should print an error message

word_set_create

Header
```
def word_set_create(filename):
```
This function reads in a text file and returns a set of all words found in the file
This function must ignore case
So "We" and "we" should count as the same word

set_difference

Header
```
def set_difference(set_1, set_2):
```
This function should create a list of all words found in the first set that were not found in the second
It should return that set

word_set_print

Header
```
def word_set_print(word_set):
```
This function prints the words in a set in alphabetical order

Test Code

Your script must contain the following statements

They should appear at the bottom of your script

file_1     = open_file_read("gettysburg.txt")
file_2     = open_file_read("gettysburg_hay.txt")
word_set_1 = word_set_create(file_1)
word_set_2 = word_set_create(file_2)
set_1_set_2_difference = set_difference(word_set_1, word_set_2)
set_2_set_1_difference = set_difference(word_set_2, word_set_1)
print()
print('Words in the first text not found in the second')
word_set_print(set_1_set_2_difference)
print()
print('Words in the second text not found in the first')
word_set_print(set_2_set_1_difference)

This code will only work if you have copied ettysburg.txt and gettysburg_hay.txt into the same directory as your script
You will find these files in /home/ghoffman/course_files/it116_files

Output

The output should look something like this

Words in the first text not found in the second
advanced
battle
field
fought
god
under

Words in the second text not found in the first
battlefield
carried
upon

Suggestions

Write this script in stages
Test your script at each step
Print the steps below
And check them off as you finish each one

Create a file with the hashbang line.
Copy and paste the headers for each of the three functions into the scrpt.
The code block for each of these functions should be the single Python statement pass.
Pass does nothing but it will keep the code from giving syntax errors.
Run the code.
You should see nothing.
If you have errors, fix them.
Copy the definition of open_file_read from hw4.py into your script.
Copy the test code to the bottom of your script.
Place a # character before each line of the test script except the first two lines.
This will stop these statements from running for now.
This is called "commenting out the code.
Run the script and fix any errors you find.
Remove the pass statement from word_set_create.
Create an empty set called word_set.
Print word_set.
Run the script and fix any errors you find.
Remove the print statement above.
Replace it with a for loop that prints each line in the file.
Run the script and fix any errors you find.
Before the print statement, write an assignment statement that turns line into lowercase using the lower string method.
Run the script and fix any errors you find.
Remove the print method and replace it with an assignment statement that creates the variable word_list by running the split() method on line.
Print word_list.
Run the script and fix any errors you find.
Remove the previous print statement.
In its place write a for loop that prints each word in word_list.
Run the script and fix any errors you find.
Replace the print statement with a statement that adds word to word_set.
Outside both for loops, print word_set.
Run the script and fix any errors you find.
Remove the final print statement.
Replace it with a statement that returns word_set.
Remove the pass statement from set_difference.
Replace it with a statement that prints the value of the parameters set_1 and set_2.
Run the script and fix any errors you find.
Remove the print statement. In it's place write an assignment statement that sets the difference between set_1 and set_2 to the variable difference.
Print difference.
Run the script and fix any errors you find.
Replace the print statement above with a statement that returns difference.
Replace the the pass statement in word_set_print with a statement that prints the parameter word_set.
Remove the # from the test code.
Run the script and fix any errors you find.
Replace the print statement in word_set_print with a for loop that prints each element of the set.
Run the script and fix any errors you find.
Change the for loop so it prints the words in alphabetical order.
Run the script and fix any errors you find.

Output

Your output should look something like this:

Cannot open file xxxxxxx

Words in the first text not found in the second
advanced
battle
field
fought
god
under

Words in the second text not found in the first
battlefield
carried
upon

Copy the file to Unix

Open FileZilla and connect to pe15.cs.umb.edu
You will have to connect using your Unix username and password.
Go to your it117 directory
Go to your hw directory
Create a directory for this exercise
Right-click in the whitespace and create the hw5 directory
Copy the script to the to hw5
Click and drag the file from the bottom left panel to the bottom right panel
Make the script executable
Right-click on the file and select "Permissions" from the menu
Enter 755 in the box provided

Testing on Your Machine

Open IDLE
Use the Open command in IDLE to open hw5.py
Under the Run menu, select Run Module

Your output should look something like this

Words in the first text not found in the second
advanced
battle
field
fought
god
under

Words in the second text not found in the first
battlefield
carried
upon

Copy the Script to Unix

Open FileZilla and connect to pe15.cs.umb.edu
Go to your it117 directory
Go to your hw directory
Right-click in the whitespace inside the hw directory
Enter hw5 in the dialog box
Click and drag your script from the bottom left panel to the bottom right panel
Right-click on the file and select "Permissions" from the menu
Enter 755 in the box provided
This will make the script executable
Click and drag gettysburg.txt and gettysburg_hay.txt from the bottom left panel to the bottom right panel

Testing the Script on Unix (Optional)

Connect to pe15.cs.umb.edu using an ssh client like putty.exe (Windows) or ssh (Mac)
Go to the directory for this exercise
```
cd  it117/hw/hw5
```
Run this script
```
python3 hw5.py
```

You should see something like this

Words in the first text not found in the second
advanced
battle
field
fought
god
under

Words in the second text not found in the first
battlefield
carried
upon