• 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 26th 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 and performs various operations on them
• The script must contain 4 functions
  • div_three_list_create
  • odds_count
  • triple_list
  • max_min_list

Functions

div_three_list_create

• Header

  def div_three_list_create(min, max, length):

• This function has three parameters, the integers min, max and length
• This function creates a list of random integers divisible by three
• The function should use the following algorithm

	create the empty list list
	for i running from 0 to length of list:
	   create a random integer num using random.randint()
	   if num is evenly divisible by three:
	      append num to list
	return list

odds_count

• Header

  def odds_count(list):

• This function has one parameter, list, a list of integers
• The function counts the number of odd integers in the list and returns that number
• The function should use the following algorithm

   set odd_count to 0
   for each number in list:
      if number is odd:
         add 1 to  odd_count
   return odd_count
	

triple_list

• Header

  def triple_list(list):

• This function has one parameter, list, a list of integers
• The functions changes each number in the list by multiplying the value by 3
• Hint: see Changing Elements Using Indexes
• The function should use the following algorithm

   for index runing from 0 to the length of list:
      set the variable number to the entry in list with position index
      give number a new value by multiplying it by 3
      use this new value of number to replace the entry in list specified by index
	

max_min_list

• Header

  def max_min_list(list):

• This function has one parameter, list, a list of integers
• The function should return the highest and lowest number in the list
• The function should use the following algorithm

   sort list
   set first to the first value in list using an index
   set last to the last value in list using an index
   return first and last
	

Test Code

• Your script must contain the following statements

  random.seed(97)
  div_three_list_create(25, 100, 15)
  num_list = div_three_list_create(25, 100, 15)
  print(num_list)
  odds_count(num_list)
  print(odds_count(num_list))
  triple_list(num_list)
  print(num_list)
  max_min_list(num_list)
  max, min = max_min_list(num_list)
  print(max, min)

• They should appear at the bottom of your script

Output

• The output should look something like this

  [60, 48, 27, 99, 90, 27, 96, 81, 30, 93, 93, 96, 81, 51, 48]
  8
  [180, 144, 81, 297, 270, 81, 288, 243, 90, 279, 279, 288, 243, 153, 144]
  297 81 

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 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. Import the random module.
   Remove the pass statement from div_three_list_create.
   Create an empty list.
   Write a while loops that keeps running as long as the length of the list is less than length.
   Inside the loop assign the variable num a random integer by calling randint.
   Print num.
   Append num to the list.
   Copy all of the test code to the bottom of your script.
   Comment out all but the first two 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 and append statements.
   Replace them with an if statement that runs if num is evenly divisible by 3.
   You will need to use the % operator.
   Inside the loop print num.
   Then append num to the list.
   Run the script.
   Fix any errors you find.
4. Remove the print statement.
   Outside the for loop, return the list.
   Uncomment the next two lines in the test code.
   Run the script.
   Fix any errors you find.
5. Remove the pass statement from odds_count.
   Replace it with a statement that creates the variable odd-count and sets its value to 0.
   Write a for loop over list.
   Inside the loop print each number.
   Uncomment the next line in the test code.
   Run the script.
   Fix any errors you find.
6. Remove the print statement.
   Replace it with an if statement that runs if num is odd.
   You will need to use the % operator.
   Inside the if statement print num.
   Run the script.
   Fix any errors you find.
7. Remove the print statement.
   Replace it with a statement that increments odds_count.
   Outside the for loop return odds_count.
   Uncomment the next line in the test code.
   Run the script.
   Fix any errors you find.
8. Remove the pass statement from triple_list.
   Write a for loop that creates indexes for each entry in the loop.
   Inside the loop use the index to print the value of each number.
   Uncomment the next line in the test code.
   Run the script.
   Fix any errors you find.
9. Remove the print statement.
   Use the index and the augmented assignment operator *= to change the value of the entry by multiplying it by 3.
   Uncomment the next line in the test code.
   Run the script.
   Fix any errors you find.
10. Remove the pass statement from max_min_list.
    Replace it with a statement that sorts the list.
    Print the list.
    Uncomment the next line in the test code.
    Run the script.
    Fix any errors you find.
11. Remove the print statement.
    Replace it with a statement that returns the last and first number in the list.
    Uncomment the last two lines 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 hw11.py
• Run your script inside IDLE
• Your output should look something like this

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

  ./hw11.py

• You should see something like this

  [60, 48, 27, 99, 90, 27, 96, 81, 30, 93, 93, 96, 81, 51, 48]
  8
  [180, 144, 81, 297, 270, 81, 288, 243, 90, 279, 279, 288, 243, 153, 144]
  297 81

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