Frank, Ian and Glen’s Letters

FIGlet, named after Frank, Ian, and Glen’s letters, is a program from the early 1990s for making large letters out of ordinary text, a form of ASCII art:

 _ _ _          _   _     _
| (_) | _____  | |_| |__ (_)___
| | | |/ / _ \ | __| '_ \| / __|
| | |   <  __/ | |_| | | | \__ \
|_|_|_|\_\___|  \__|_| |_|_|___/

Among the fonts supported by FIGlet are those at figlet.org/examples.html.

FIGlet has since been ported to Python as a module called pyfiglet.

In a file called figlet.py, implement a program that:

Expects zero or two command-line arguments:
- Zero if the user would like to output text in a random font.
- Two if the user would like to output text in a specific font, in which case the first of the two should be -f or --font, and the second of the two should be the name of the font.
Prompts the user for a str of text.
Outputs that text in the desired font.

If the user provides two command-line arguments and the first is not -f or --font or the second is not the name of a font, the program should exit via sys.exit with an error message.

Hints

You can install pyfiglet with:
```
pip install pyfiglet
```
The documentation for pyfiglet isn’t very clear, but you can use the module as follows:
```
from pyfiglet import Figlet

figlet = Figlet()
```
You can then get a list of available fonts with code like this:
```
figlet.getFonts()
```
You can set the font with code like this, wherein f is the font’s name as a str:
```
figlet.setFont(font=f)
```
And you can output text in that font with code like this, wherein s is that text as a str:
```
print(figlet.renderText(s))
```
Note that the random module comes with quite a few functions, per docs.python.org/3/library/random.html.

Demo

This demo’s first output used a random font. Your output may vary.

Before You Begin

Log into cs50.dev, click on your terminal window, and execute cd by itself. You should find that your terminal window’s prompt resembles the below:

Next execute

mkdir figlet

to make a folder called figlet in your codespace.

Then execute

cd figlet

to change directories into that folder. You should now see your terminal prompt as figlet/ $. You can now execute

code figlet.py

to make a file called figlet.py where you’ll write your program.

How to Test

Here’s how to test your code manually:

Run your program with python figlet.py test. Your program should exit via sys.exit and print an error message:
```
Invalid usage
```
Run your program with python figlet.py -a slant. Your program should exit via sys.exit and print an error message:
```
Invalid usage
```
Run your program with python figlet.py -f invalid_font. Your program should exit via sys.exit and print an error message:
```
Invalid usage
```

Run your program with python figlet.py -f slant. Type CS50. Your program should print the following:

   ___________ __________ 
  / ____/ ___// ____/ __ \
 / /    \__ \/___ \/ / / /
/ /___ ___/ /___/ / /_/ / 
\____//____/_____/\____/  

Run your program with python figlet.py -f rectangles. Type Hello, world. Your program should print the following:

 _____     _ _                        _   _ 
|  |  |___| | |___      _ _ _ ___ ___| |_| |
|     | -_| | | . |_   | | | | . |  _| | . |
|__|__|___|_|_|___| |  |_____|___|_| |_|___|
                  |_|                       

Run your program with python figlet.py -f alphabet. Type Moo. Your program should print the following:

M   M         
MM MM         
M M M ooo ooo 
M   M o o o o 
M   M ooo ooo                     