IT 116: Intermediate Scripting

IT 116: Introduction to Scripting
Homework 10

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 23rd at 11:59 PM

What You Need to Do

Create the script hw10.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 hw10 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 hw10.py
Using FileZilla, copy the file temps.txt from /home/ghoffman/course_files/it116_files to the directory on your machine that holds hw10.py

Specification

This script will read a file that records temperatures for different dates

The data in the file looks like this

2020-11-01	0
2020-11-02	1
2020-11-03	0
...

The script calculates the average, maximum and minimum temperatures from this file using lists
The script must contain 3 functions
- temp_list_from_file
- mean_temp
- max_min_temp

Functions

temp_list_from_file

Header
```
 def temp_list_from_file(file):
```
This function will read in a file containing values for date and temperature and return a list of temperatures
The temperatures must be converted into integers

mean_temp

Header
```
def mean_temp(list):
```
The function has one parameter, list, a list of integer temperatures
It must return the average temperature, rounded to an integer
The function should use the following algorithm

	set total to 0
	for each temp in the list:
	   add temp to total
	find the mean by dividing total by the length of the list
	return the mean using round to turn it into an integer

max_min_temp

Header
```
def max_min_temp(list):
```
The function must return the maximum and minimum temperature
The function should use the built in functions max and min

Test Code

Your script must contain the following statements

FILENAME  = "temps.txt"
file      = open(FILENAME, "r")
temp_list = temp_list_from_file(file)
mean = mean_temp(temp_list)
print(mean)
max_min_temp(temp_list)
max_temp, min_temp = max_min_temp(temp_list)
print(max_temp, min_temp)

They should appear at the bottom of your script

Output

The output should look something like this
```
77
89 66
```

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 hashbang line on the first line of the script.
Copy only the function headers for the three 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.
Remove the pass statement from temp_list_from_file.
Replace it with a statement that creates the empty list list.
Write a for loop that prints every line in the file.
Add the test code to the bottom of the sfgcript.
Comment out all but the first three lines of the test code.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that uses split on the line to assign values to the variables date and temp.
Print temp.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that turns each temp value into an integer and appends temp to list.
Outside the for loop print list.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that returns list.
Remove the pass statement from mean_temp.
Replace it with a statement that sets total to 0.
Print the parameter list.
Uncomment the next line in the test code.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a for loop over list using temp as the loop variable.
Inside the loop print temp.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that adds temp to total.
Outside the for loop print total.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that sets average to total divided by the length of list.
Print average.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a return statement that returns average turned into an integer using round.
Uncomment the next line in the test code.
Run the script.
Fix any errors you find.
Remove the pass statement from max_min_temp.
Replace it with a statement that sets maximum by running max on list.
Add as statement that sets minimum by running min on list.
Print maximum and minimumn.
Uncomment the next line in the test code.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that returns the maximum and the minimum.
Uncomment the last 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 hw10.py
Run your script inside IDLE
Your output should look something like this
```
77
89 66
```
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 hw10 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 temps.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/hw10
```
Run this script
```
./hw10.py
```
You should see something like this
```
 77
89 66
```