IT 116: Introduction to 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

Sunday, April 20th 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 rainfall.txt from /home/ghoffman/course_files/it116_files.

Specification

This script will read in a text file and create a list of rainfall on different days
It will use this list to compute the average rainfall and the maximum rainfall
The script must contain 3 functions
- rain_list_from_file
- average_rain
- max_rain

Functions

rain_list_from_file

Header
```
def rain_list_from_file(file):
```
The function must read in a file with entries like this
```
2020-11-01	0
2020-11-02	1
2020-11-03	0
```
The parameter file is a file object on this file
The function must read in the file with a for loop
And return a list containing just the values for rain
The rain values should be integers

average_rain

Header
```
def average_rain(list):
```
The parameter list is a list of the rain that fell on each day
The function must calculate the average to 2 decimal places and return that value

max_rain

Header
```
def max_rain(list):
```
The parameter list is a list of the rain that fell on each day
The function must find the maximum rainfall in the list and return that value

Test Code

Your script must contain the following statements

FILENAME = "rainfall.txt"
file = open(FILENAME, "r")
rain_list = rain_list_from_file(file)
average = average_rain(rain_list)
print(average)
max_rain = max_rain(rain_list)
print(max_rain)

They should appear at the bottom of your script

Output

The output should look something like this
```
1.23
6
```

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

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.
In rain_list_from_file remove the pass statement.
Write a statement that creates an empty list and assign it to the variable list.
Now write a for loop that loops through the file.
Inside the loop print each line.
Copy the test code to the bottom of the file.
Comment out the last 4 lines of the test code.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that assign values to the variables date and rain by running split on line.
Now turn rain into an integer using the int conversion function.
Print these variables.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a line that appends rain to list.
Outside the for print list.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that returns list.
In average_rain remove the pass statement.
Replace it with a statement that prints list.
Remove the # from the line in the test code that calls average_rain.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that sets the value of the variable total to 0.
Write a for loop that loops through the list.
Inside the loop print each value in the list.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that adds the loop variable to total.
Outside the loop, print total.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that calculates the average and assigns it to the value average.
You should use the length of the list in calculating the average.
Print average.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that returns average rounded to 2 decimal places.
Remove the # from the line in the test code that prints average.
Run the script.
Fix any errors you find.
In max_rain remove the pass statement.
Replace with a statement that prints list.
Remove the # from the line in the test code that calls max_rain.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a line that sets the value of max to 0.
Write a for loop that loops over the values in the list.
Inside the loop print each value.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with an if statement that prints the loop variable if it is larger than max.
Run the script.
Fix any errors you find.
Remove the print statement in the if statement.
Replace it with a statement that sets max to the loop variable.
Outside the for loop, print max.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with a statement that returns max.
Remove the # from 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 hw10.py
Run your script inside IDLE
Your output should look something like this
```
1.23
6
```
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 rainfall.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
```
python3 hw10.py
```
You should see something like this
```
1.23
6
```