Basic validating of the email address in python

I saw some regex strings for validing email address that I didn't fully understand so I tried to make it without regex. If I was to make regex for validating email it would look something like this:
re.compile("\w+@\w+[.][A-Za-z]{2,}", re.I | re.A)

Ah, well this is code I was working on:

https://pastebin.com/yiXM9p5a


 
If you need to test out some python code and you don't have python installed on computer but you have internet connection (that's fast enough) you can test your code here.

Links:
https://docs.python.org/3/howto/regex.html?highlight=regular%20expression - HOWTO: Regular Expression (Python)
https://repl.it/ - Online Python and more other languagues.
http://pastebin.com/vRPfSFyN (Until June 9th 2017)
http://pastebin.com/0BKrwwhT