IT 116: Introduction to Scripting

IT 116: Introduction to Scripting
Homework 9

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, November 10th 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
Copy the file temps_max_min.txt from /home/ghoffman/course_files/it116_files.
Use FileZilla to do this.

Specification

This script will read in a file
The file temps_max_min.txt has three values on each line
- Date
- Maximum temperature
- Minimum temperature

The file looks like this

2017-06-01 67 62
2017-06-02 71 70
2017-06-03 69 65
...

The script will create a new file with the date and the average temperature
It will then find the highest average temperature
And the date on which it occurred
This script must contain two functions
- average_day_temp
- max_month_average

Functions

average_day_temp

Header

def average_day_temp(in_file, out_file):

The function will read in a file like the one above
The the parameter in_file is a file object for reading on this file
The the parameter out_file is a file object for writing on the file to which output will be sent
The function will run through the input file with a for loop, reading in values for date, max and min
It will then calculate the rounded average for each day
And write the date and average to the output file

Which will look like this

2017-06-01  64
2017-06-02  70
2017-06-03  67
...

max_month_average

Header
```
def max_month_average(in_file):
```
The the parameter in_file is a file object on a file containing dates and average temperatures
This function will loop through this file to find the the highest average temperature and the date on which it occurred
It will return this and temperature

It should use the following algorithm

set max_temp to 0
set max_date to the empty string
for each line in the file
   get the date and temperature
   turn the temperature into an integer
   if the temperature is greater than max_temp
      set max_temp to temperature
      set max_date to the date
return max_date and max_temp

Test Code

Your script must contain the following statements

MIN_MAX_FILENAME = "temps_max_min.txt"
AVERAGE_FILENAME = "temps_average.txt"
min_max_file     = open(MIN_MAX_FILENAME, "r")
average_file     = open(AVERAGE_FILENAME, "w")
average_day_temp(min_max_file, average_file)
average_file     = open(AVERAGE_FILENAME, "r")
max_month_average(average_file)
average_file     = open(AVERAGE_FILENAME, "r")
date, highest_temp = max_month_average(average_file)
print(date, highest_temp)

They should appear at the bottom of your script

Output

The output should look something like this
```
2017-06-12 86
```

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 the script hw9.py.
Copy the two function headers into your script.
For the body of these functions, use the pass statement.
Run the script.
Fix any errors you find.
Remove the pass statement from average_day_temp.
Replace it with a for loop over the input file.
Inside the loop, print each line.
Copy the test code to the bottom of the script.
Comment out all first 5 lines.
Run the script.
Fix any errors you find.
Remove the print statement.
In it's place write one assignment statement that gives values to the variables, date, max and min by calling split() on each line.
Print the values of date, max and min.
Run the script.
Fix any errors you find.
Remove the print statement.
Covert both max and min into integers using assignment statements.
Calculate average by adding max and min and dividing the sum by 2.
Don't forget to use round.
Print average.
Run the script.
Fix any errors you find.
Remove the print statement.
Create the string out_line consisting of date, a tab (\t), average and a newline (\n).
Use concatenation to create this string.
Don't forget to convert average to a string using str.
Write out_line to the out file.
Run the script.
Look at the contents of the temps_average.txt
Fix any errors you find.
Remove the pass statement from max_month_average.
Set the variable max_temp to 0.
Set the variable max_date to the empty string.
Print max_temp and max_date.
Uncomment the next two lines in the test code.
Run the script.
Fix any errors you find.
Write a for loop over the file and print each line.
Run the script.
Fix any errors you find.
Remove the print statement.
Write an assignment statement giving values to the variables date and temp by calling split() on each line.
Print date and temp.
Run the script.
Fix any errors you find.
Remove the print statement.
Replace it with an assignment statement that converts temp into an integer.
Write an if statement that that tests whether temp is greater than max_temp.
Inside the if statement set max_temp to temp and max_date to date.
Then print max_date and max_temp.
Run the script.
Fix any errors you find.
Remove the print statement.
Outside the for loop, return max_date and max_temp.
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 hw9.py
Run your script inside IDLE
Your output should look something like this
```
2017-06-12 86
```

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 temps_max_min.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
```
python3 hw9.py
```
You should see something like this
```
2017-06-12 86
```