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Lab 4: Temp Solution
Introduction
Lab 4 is your first Python script and it is a simple one. It is your first interactive script, meaning your script will prompt the user to enter a temperature in degrees Fahrenheit or Celsius and calculate the other, in a continuous loop until the user exits the program.
Requirements
Your script shall be named temp and be marked executable. Here is how you execute your script:
./temp
Your script shall interact with the user. The first thing it should print is exactly this:
Welcome to the CS 3030 Temperature Conversion Program
This welcome message should be printed only once.
Your program should then loop until the user enters 3 , followed by ENTER to exit the program. Your script should prompt the user with this main menu (note the spacing, colons and number of commas):
BASH
Main Menu
1:Fahrenheit to Celsius
2:Celsius to Fahrenheit
3:Exit program
Please enter 1, 2 or 3:
The user then enters 1 , 2 or 3 (and hits ENTER )
If the user enter 3 , the program exits.
If the user enters a 1 , the user is prompted for degrees Fahrenheit with this prompt:
Please enter degrees Fahrenheit:
The user enters a number, which should not contain commas but can contain a decimal point or a minus sign.
Assume the user enters 56.2 . The program should respond with:
56.2 degrees Fahrenheit equals 13.4 degrees Celsius
The program then reprints the main menu and prompts the user again, in an endless loop.
If the user enters a 2 , the user should be prompted for degrees Celsius with this prompt:
Please enter degrees Celsius:
The user enters a number as before, which should not contain commas but can contain a decimal point or a minus sign. Assume the user enters 91.8 . The program should respond with:
91.8 degrees Celsius equals 197.2 degrees Fahrenheit
If at any time the user enters anything non-numeric (including typing nothing and hitting just ENTER ), your script should trap the error and at a minimum, print a message that includes:
Invalid entry
You should then reprint the main menu and start over at the beginning. Do not re-prompt for the degrees, start over at the top. Do not reprint the Welcome message.
Your script should include these two functions to calculate its results (yes, you should use floating point numbers):
def fahrenheitToCelsius(fahrenheit)
converts degrees fahrenheit to degrees celsius using this formula: C = (F - 32.0) * (5.0/9.0)
def celsiusToFahrenheit(celsius)
converts degrees celsius to degrees fahrenheit using this formula: F = (9.0/5.0) * C + 32.0
Hints
Use try/except to trap errors when prompting the user or converting the incoming string to a number
Always restart from the main menu when the user enters anything invalid Always restart from the main menu after calculating degrees
Your script should expect the user to hit ENTER after each entry
Exit immediately when the user enters 3 from the main menu
Use whitespace and indenting to make your script readable
Add comments to your script to document your logic
Run cucumber to check your progress
Cowan 01-29-2019 03:07 PM 2
Because temp is interactive, the first thing you should implement and test is typing 3 to exit. The cucumber scripts rely on this feature and it must work.
Clone your private repo on github.com
In the assignment module in Canvas, find the link to the Canvas page entitled "Clone your Lab 4 Repo", click on it and follow the instructions.
Copy your private repo down to icarus
BASH
git clone https://github.com/cowancs3030spring19/lab4-YOURGITHUBUSERNAME
cd lab4-YOURGITHUBUSERNAME
Write and test temp
Fire up your favorite text editor, and begin with your header:
#!/usr/bin/python
TEXT
(Your name)
Lab 4 - Temp
CS 3030 - Scripting Languages
(Add your amazing, perfect code here)
If your temp script hangs when you run it, and you have to close and reopen your terminal session, it is possible that your script will continue to run in the background on icarus. It will then slowly consuming all available disk space. When this happens, icarus crashes and the Lab assistants in Ogden will know it is you and hunt you down. If at any time you suspect this might be the case, execute the ps command to display all of your running processes:
ps
You should get something that looks like this:
The 5 digit numbers on the left are process IDs (pids). If you see any other processes than the ones in the above example, issue the kill command to terminate each process, substituting the pid number for PID (don’t kill the bash process or you will be logged out).
Cowan 01-29-2019 03:07 PM 3
kill PID
The cucumber files for this lab implements a random number generator for the °C and °F values.
To ensure your program always produces the correct output, test your program many, many times with various input. Then run cucumber many, many times.
./cucumber -s
Submit your assignment code for grading
Remember, you must push your script in your private repo to github.com to receive any points, for all assignments in this course.
BASH
git add temp
git commit -m"COMMIT MESSAGE"
git push origin master
Files created for this lab
temp
Grading
Here is how you earn points for this assignment:
Cowan 01-29-2019 03:07 PM 4
FEATURES
POINTS
Must-Have Features
Script is named correctly and found in its proper place in your repo
5
Script is executable
5
Required Features
Script prints “Welcome to the CS 3030 Temperature Conversion Program”
5
Script prints the Main Menu
5
Script correctly converts degrees Fahrenheit to degrees Celsius with 1 decimal place
10
with option 1
Script correctly converts degrees Celsius to degrees Fahrenheit with 1 decimal place
10
with option 2
Script exits with option 3
10
Script uses function fahrenheitToCelsius()
10
Script uses function celsiusToFahrenheit()
10
Script recovers from non-numeric entry at main menu
10
Script recovers from non-numeric entry when prompting for degrees Fahrenheit
10
Script recovers from non-numeric entry when prompting for degrees Celsius
10
Grand Total
100
Cowan 01-29-2019 03:07 PM
5
