• 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

Thursday, October 30th at 11:59 PM

What You Need to Do

• Create the script hw11.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 hw11 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 hw11.py

Specification

• This script creates a list of random integers
• Then finds the average, maximum and count of the even numbers in this list
• The script must contain 4 functions
  • random_number_list
  • list_average
  • list_maximum
  • list_evens

Functions

random_number_list

• Header

  def random_number_list(min, max, length):

• This function creates a list of random integers
• The number of entries in the list is specified by the parameter length
• The numbers created must be between the values given by the parameters min and max
• The function returns the list it has created
• The function should use the following algorithm

	create an empty list
	loop for the number of times specified by length
	   create a random integer with a value between 
	   max and min
	   append this integer to the list
	return the list

list_average

• Header

  def list_average(list):

• This function calculates the average value of the numbers in the list specified by the parameter list
• The average must be rounded to the nearest integer
• The function must return this average
• The function should use the following algorithm

	set total to 0
	for each number in the list:
	   add it to total
	calculate the average by dividing total by the length of the list
	return the rounded average

list_maximum

• Header

  def list_maximum(list):

• This function determine the the highest number in the list specified by the parameter list
• The function must return this maximum value
• The function should use the following algorithm

	set max to 0
	for each number in the list:
	   if number is greater than max:
	      set max to number
	return max

list_evens

• Header

  def list_evens(list):

• This function counts the even numbers in a list specified by the parameter list
• The function must return this count
• The function should use the following algorithm

	set even_count to 0
	for each number in the list:
	   if the number is even:
	      increase even_count by 1
	return even_count

Test Code

• Your script must contain the following statements

  random.seed(89)
  num_list = random_number_list(50, 100, 20)
  average  = list_average(num_list)
  print(average)
  max = list_maximum(num_list)
  print(max)
  even_count = list_evens(num_list)
  print(even_count)

• They should appear at the bottom of your script

Output

• The output should look something like this

  73
  99
  10

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.
   Import the random module.
   Copy only the function headers for the four 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 statement from random_number_list.
   Replace it with a statement that creates an empty list.
   Write a for loop that will run the number of times specified by length.
   Inside the loop, print the value of the loop variable.
   Copy the test code to the bottom of the script.
   Comment out all but the first two lines of the test script.
   Run the script.
   Fix any errors you find.
3. Remove the print statement.
   Replace it with an assignment statement that give num a value created by a call to randint in the random module.
   You will need to use min and max as arguments to randint.
   Print num.
   Run the script.
   Fix any errors you find.
4. Remove the print statement.
   Replace it with a statement that appends num to list.
   Outside the loop print list.
   Run the script.
   Fix any errors you find.
5. Remove the print statement.
   Replace it with a statement that returns list.
   Remove the pass statement from list_average.
   Replace it with a statement that prints list.
   Uncomment the next line in the test code.
   Run the script.
   Fix any errors you find.
6. Remove the print statement.
   Replace it with a line that sets total to 0.
   Write a for loop over list using num as the loop variable.
   Inside the loop print num.
   Run the script.
   Fix any errors you find.
7. Remove the print statement.
   Replace it with a statement that adds num to total.
   Outside the loop print total. Run the script.
   Fix any errors you find.
8. Remove the print statement.
   Replace it with a statement that calculates average by dividing total by the length of list. Print average.
   Run the script.
   Fix any errors you find.
9. Remove the print statement.
   Replace it with a statement that returns the rounded value of average.
   Uncomment the next line in the test code.
   Run the script.
   Fix any errors you find.
10. Remove the pass statement from list_maximum.
    Replace it with a statement that sets max to 0.
    Write a for loop over list that uses num as the loop variable.
    Inside the for loop print num.
    Uncomment the next line in the test code.
    Run the script.
    Fix any errors you find.
11. Remove the print statement.
    Replace it with an if statement that will run if num is greater than max.
    Inside the if statement set max to num.
    Print max.
    Run the script.
    Fix any errors you find.
12. Remove the print statement.
    Outside the for loop return max.
    Uncomment the next line in the test code. Run the script.
    Fix any errors you find.
13. Remove the pass statement from list_evens.
    Set even_count to 0. Write a for loop over list that uses num as the loop variable.
    Inside the for loop print num.
    Uncomment the next line in the test code. Run the script.
    Fix any errors you find.
14. Remove the print statement.
    In its place write an if statement that will run if num is even.
    A number is even if its remainder when divided by 2 is 0.
    Inside the if statement print num.
    Run the script.
    Fix any errors you find.
15. Remove the print statement.
    Replace it with a statement that adds 1 to even_count.
    Outside the for loop return even_count.
    Uncomment the last line of 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 hw11.py
• Run your script inside IDLE
• Your output should look something like this

  73
  99
  10

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 hw11 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

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/hw11

• Run this script

  python3 hw11.py

• You should see something like this

  73
  99
  10

Copyright © 2022 Glenn Hoffman. All rights reserved. May not be reproduced without permission.