COP3504CLab 03- The Cow Says… Solution

Lab 03: The Cow Says…
Overview
This lab is designed to introduce students to the Bash Command Line Interface (CLI) and the concept of CLI arguments and give them practice writing classes. For (only) this lab, you are not allowed to use any windowed editor (such as IntelliJ, Eclipse, or Notepad++). Instead, you will use a Unix-based command line editor.

The cowsay utility is a popular Unix program from the 20th century (see https://en.wikipedia.org/wiki/Cowsay). You will write a slightly simplified cowsay program that takes in several arguments and prints out different text depending on the arguments. You must log in to the school computers using your CISE account to do this lab.

Tools
Please note that you must use a text editor and the terminal to edit and run your program and its directories. It is advised students learn/review basic Unix shell commands before beginning; a good run-through can be found here: https://linuxjourney.com/lesson/the-shell.

Follow these steps to get started on the lab:

1) Open a terminal and enter the pwd command to identify the path to the working (current) directory (folder) 2) Enter ls to list the contents of the current directory
3) Use the mkdir command to make a new directory called CowLab.
4) Use ls to see the change, then cd to change to the directory CowLab.
5) Do your lab work in that folder. Use your googlefu skills to find more commands.

Recommended text editors include nano and joe. (If you hate yourself, you can use vi or emacs too.) You’ll also need to use the python3 program to execute Python programs. You can also use its interactive shell for testing.

You can read more information about some of these commands here: https://www.howtogeek.com/howto/42980/the-beginners-guide-to-nano-the-linux-command-line-text-editor/ https://introcs.cs.princeton.edu/java/15inout/linux-cmd.html

History of Command Line Names (Just for Fun)
Students will construct one module which (cowsay) which will contain a main() method as the entry point (for command line execution) and a data class (Cow). Note: heiferfactory.py is provided for you; your code must use this module to create cow objects. All attributes / methods must be private unless noted in the specification!
Provided For Students – heiferfactory

get_cows() -> list[Cow]
Returns an array of cow objects from the built-in data set. This will call the Cow constructor and set_image() methods of the cow class to properly initialize new cow objects uniquely for each data set.
Entry Point

The command line arguments that must be supported are as follows:

python3 cowsay.py -l Lists the available cows (this is “dash ell”!) python3 cowsay.py MESSAGE Prints out the MESSAGE using the default COW python3 cowsay.py -n COW MESSAGE Prints out the MESSAGE using the specified COW

If a user calls for a cow that does not exist, the program should print out “Could not find [COWNAME] cow!”

Output Samples

>python3 cowsay.py I am a potato!

I am a potato!

^__^
(oo)_______
(__) )/
||----w |
|| || >python3 cowsay.py -n kitteh I am pritteh.

I am pritteh.

("`-' '-/") .___..--' ' "`-._
` *_ * ) `-. ( ) .`-.__. `)
(_Y_.) ' ._ ) `._` ; `` -. .-'
_.. `--'_..-_/ /--' _ .' ,4
( i l ),-'' ( l i),' ( ( ! .-'

>python3 cowsay.py -l
Cows available: heifer kitteh

>python3 cowsay.py -n ninja WUT
Could not find ninja cow!

Suggested Methods
The following methods are suggested to make development easier, but are not required:

_list_cows(cows: list[Cow])
Displays the list of available cows from an array of Cow objects.

_find_cow(name: str, cows: list[Cow])
Given a name and an array of Cow objects, return the Cow object with the specified name.

Cow Class
The Cow class facilitates the creation and use of cow objects by providing the following methods (which students must implement):

__init__(self, name: str)
This method should be the only constructor for this class. There should not be a default constructor!

get_name(self) -> str
Returns the name of the cow.

get_image(self) -> str
Returns the image used to display the cow (after the message).

set_image(self, _image: str)
Sets the image used to display the cow (after the message).
Submissions
NOTE: Your output must match the example output *exactly*. If it does not, you will not receive full credit for your submission!

Files: cowsay.py cow.py
Method: Submit on Zybooks

Sample Output

>python3 cowsay.py Hello World!

Hello World!

^__^
(oo)_______
(__) )/
||----w |
|| ||

>python3 cowsay.py -n kitteh Hello World!

Hello World!

("`-' '-/") .___..--' ' "`-._
` *_ * ) `-. ( ) .`-.__. `)
(_Y_.) ' ._ ) `._` ; `` -. .-'
_.. `--'_..-_/ /--' _ .' ,4
( i l ),-'' ( l i),' ( ( ! .-'

>python3 cowsay.py -l
Cows available: heifer kitteh

>python3 cowsay.py -n ninja Hello world!
Could not find ninja cow!

>python3 cowsay.py Hello -n kitteh

Hello -n kitteh

^__^
(oo)_______
(__) )/
||----w |
|| ||