• 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, April 7th at 11:59 PM

What You Need to Do

• Create the script hw9.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 hw9 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 hw9.py
• Using FileZilla, copy the file id_scores.txt from /home/ghoffman/course_files/it116_files to the directory on your machine that holds hw9.py
  

Specification

• This script will read a file with student IDs and exam scores and compute the average, highest and lowest scores
• The data in the file looks like this

  07128669	76
  09423988	88
  07765600	94
  ...

• The script must contain 2 functions
  • average_score
  • highest_lowest_score

Functions

average_score

• Header

  def average_score(file):

• The function has one parameter, file, a file object
• The function must read in the file with a for loop to get the score for each student
• It must turn the score into an integer and use it to calculate the average score
• It must return the average score, rounded to an integer
• The function should use the following algorithm

	set count to 0
	set total to 0
	for each line in the file:
		get the values for id and score
		turn score into an integer
		add score to total
		increment count by 1
	find the average by dividing total by count
	return the average using round to turn it into an integer
	

highest_lowest_score

• Header

  def highest_lowest_score(file):

• The function has one parameter, , a file object
• The function must read in the file with a for loop to get the score for each student
• It must turn the score into an integer and use it to calculate the highest and lowest scores
• The function must return the highest and lowest scores
• The function should use the following algorithm

	set max_score to 0
	set min_score to 100
	for each line in the file:
		get the values for id and score
		turn score into an integer
		if score is greater than max_score:
			set max_score to score
		if score is less min_score:
			set min_score to score
	return max_score, min_score

Test Code

• Your script must contain the following statements

  FILENAME = "id_scores.txt"
  file = open(FILENAME, "r")
  average = average_score(file)
  print(average)
  file = open(FILENAME, "r")
  highest_lowest_score(file) 
  file = open(FILENAME, "r")
  highest, lowest = highest_lowest_score(file)
  print(highest, lowest)

Output

• The output should look something like this

  73
  99 40

• The text in blue is what the user enters

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

1. Create a hashbang line on the first line of the script.
   Copy only the function headers for the two functions listed above into your script file.
   Under each header, write pass.
   Make sure this statement is indented.
   Run the script.
   Fix any errors you find.
2. Remove the pass from average_score.
   Create the variables count and total giving them initial values of 0.
   Print the variables total and count.
   Copy all of the test code to the bottom of your script.
   Comment out all but the first three lines of the test code.
   Do this by inserting # at the beginning of the line.
   Run the script.
   Fix any errors you find.
3. Remove the print statement from average_score.
   In it's place write a for loop that prints every line in the file.
   Run the script.
   Fix any errors you find.
4. Remove the print statement.
   Replace it with a statement that calls split on the line to assign values to the variables id and score.
   Print id and score.
   Run the script.
   Fix any errors you find.
5. Remove the print statement.
   Replace it with an assignment statement that turns score into an integer using int().
   Next increment count.
   Write a statement that adds score to total.
   Outside the for loop, print count and total.
   Run the script.
   Fix any errors you find.
6. Remove the print statement.
   Replace it with a statement that calculates the average and assigns it to the variable average.
   The value of average is a float.
   Use an assignment statement to make average an integer using round.
   Return average.
   Uncomment the first commented line in the test code.
   Run the script.
   Fix any errors you find.
7. Remove the pass from highest_lowest_score.
   Create the variable max_score and give it the value of 0.
   Create the variable min_score and give it the value 100.
   Print the variables max_score and min_score.
   Uncomment the next three lines in the test code.
   Run the script.
   Fix any errors you find.
8. Remove the print statement from highest_lowest_score.
   In it's place write a for loop that prints every line in the file.
   Run the script.
   Fix any errors you find.
9. Remove the print statement.
   Replace it with a statement that calls split on the line to assign values to the variables id and score.
   Print id and score.
   Run the script.
   Fix any errors you find.
10. Remove the print statement.
    Replace it with an assignment statement that turns score into an integer using int().
    Write an if statement that will run if score is greater than max_score.
    Inside this if statement set max_score to score.
    Also inside the if statement print max_score.
    Run the script.
    Fix any errors you find.
11. Remove the print statement.
    After the 1st if statement write another if statement that will run if score is less than min_score.
    Inside this if statement set min_score to score.
    Also inside the if statement print min_score.
    Run the script.
    Fix any errors you find.
12. Remove the print statement.
    Outside the for loop return max_score and max_score.
    Uncomment the last line in the test code.
    Run the script.
    Fix any errors you find.

Testing on Your Machine

• Open IDLE
• Use the Open command in IDLE to open hw9.py
• Run your script inside IDLE
• Your output should look something like this

• The text in blue is what you enter at the command line

Copy the Script to Unix

• Open FileZilla and connect to pe15.cs.umb.edu
• Go to your it116 directory
• Go to your hw directory
• Right-click in the whitespace inside the hw directory
• Enter hw9 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 id_scores.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  it116/hw/hw9

• Run this script

  ./hw9.py

• You should see something like this

  73
  99 40

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