Validating and Parsing Email Addresses

A valid email address meets the following criteria:

• It’s composed of a username, domain name, and extension assembled in this format: username@domain.extension
• The username starts with an English alphabetical character, and any subsequent characters consist of one or more of the following: alphanumeric characters, -,., and _.
• The domain and extension contain only English alphabetical characters.
• The extension is 1, 2, or 3 characters in length.

Given n pairs of names and email addresses as input, print each name and email address pair having a valid email address on a new line.

Hint: Try using Email.utils() to complete this challenge. For example, this code:

import email.utils
print email.utils.parseaddr('DOSHI <DOSHI@hackerrank.com>')
print email.utils.formataddr(('DOSHI', 'DOSHI@hackerrank.com'))

produces this output:

('DOSHI', 'DOSHI@hackerrank.com')
DOSHI <DOSHI@hackerrank.com>

Input Format

The first line contains a single integer, n, denoting the number of email address.
Each line i of the n subsequent lines contains a name and an email address as two space-separated values following this format:

name <user@email.com>

Constraints

• 0 < n < 100

Output Format

Print the space-separated name and email address pairs containing valid email addresses only. Each pair must be printed on a new line in the following format:

name <user@email.com>

You must print each valid email address in the same order as it was received as input.

Sample Input

2  
DEXTER <dexter@hotmail.com>
VIRUS <virus!@variable.:p>

Sample Output

DEXTER <dexter@hotmail.com>

Explanation

dexter@hotmail.com is a valid email address, so we print the name and email address pair received as input on a new line.
virus!@variable.:p is not a valid email address because the username contains an exclamation point (!) and the extension contains a colon (:). As this email is not valid, we print nothing.

Solution Implementation

import re
import email.utils        
N = int(input())       
pattern = r'^[a-z][\w\-\.]+@[a-z]+\.[a-z]{1,3}$'
for i in range(0, N):
    parsed_addr = email.utils.parseaddr(input())
    if re.search(pattern, parsed_addr[1]):
        print(email.utils.formataddr(parsed_addr))