Response Validation

When creating a Google Form that prompts users for a short answer (or paragraph), it’s possible to enable response validation and require that the user’s input match a regular expression. For instance, you could require that a user input an email address with a regex like this one:

^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$

Or you could more easily use Google’s built-in support for validating an email address, per the screenshot below, much like you could use a library in your own code:

Google Form

In a file called response.py, using either validator-collection or validators from PyPI, implement a program that prompts the user for an email address via input and then prints Valid or Invalid, respectively, if the input is a syntatically valid email address. You may not use re. And do not validate whether the email address’s domain name actually exists.

Hints

Note that you can install validator-collection with:
```
pip install validator-collection
```
Click Homepage to find your way to the library’s documentation.
Note that you can install validators with:
```
pip install validators
```
Click Homepage to find your way to the library’s documentation.

Demo

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 response

to make a folder called response in your codespace.

Then execute

cd response

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

code response.py

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

How to Test

Here’s how to test your code manually:

Run your program with python response.py. Ensure your program prompts you for an email, then type malan@harvard.edu, followed by Enter. Your program should output Valid.
Run your program with python response.py. Type your own email, followed by Enter. Your program should output Valid.
Run your program with python response.py. Type malan@@@harvard.edu, followed by Enter. Your program should output Invalid.
Run your program with python response.py. Mistype your own email, including an extra . before .com, for example. Press enter and your program should output Invalid.

You can execute the below to check your code using check50, a program that CS50 will use to test your code when you submit. But be sure to test it yourself as well!

check50 cs50/problems/2022/python/response

Green smilies mean your program has passed a test! Red frownies will indicate your program output something unexpected. Visit the URL that check50 outputs to see the input check50 handed to your program, what output it expected, and what output your program actually gave.

How to Submit

In your terminal, execute the below to submit your work.

submit50 cs50/problems/2022/python/response