# Validating Email Addresses With a Filter in Python | HackerRank Solution

Hello coders, today we are going to solve Validating Email Addresses With a Filter HackerRank Solution in Python.

Contents

You are given an integer N followed by N email addresses. Your task is to print a list containing only valid email addresses in lexicographical order.

• It must have the [email protected] format type.
• The username can only contain letters, digits, dashes and underscores [a – z], [A – Z], [0 – 9], [_-].
• The website name can only have letters and digits [a – z], [A – Z], [0 – 9].
• The extension can only contain letters [a – z], [A – Z].
• The maximum length of the extension is 3.

Concept

filter takes a function returning True or False and applies it to a sequence, returning a list of only those members of the sequence where the function returned True. A Lambda function can be used with filters.

Let’s say you have to make a list of the squares of integers from 0 to 9 (both included).

``````>> l = list(range(10))
>> l = list(map(lambda x:x*x, l))``````

Now, you only require those elements that are greater than 10 but less than 80.

``>> l = list(filter(lambda x: x > 10 and x < 80, l))``

Example

Complete the function fun in the editor below.
fun has the following paramters:

• string s: the string to test

Returns

• boolean: whether the string is a valid email or not

## Input Format

The first line of input is the integer N, the number of email addresses.
N lines follow, each containing a string.

## Constraints

Each line is a non-empty string.

Sample Input

``````3
lara@hackerrank.com
[email protected]
[email protected]``````

Sample Output

``['[email protected]', '[email protected]', '[email protected]']``

## Solution – Validating Email Addresses With a Filter

```def fun(email):
try:
website, extension = url.split('.')
except ValueError:
return False

if username.replace('-', '').replace('_', '').isalnum() is False:
return False
elif website.isalnum() is False:
return False
elif len(extension) > 3:
return False
else:
return True

def filter_mail(emails):
return list(filter(fun, emails))

if __name__ == '__main__':
n = int(input())
emails = []
for _ in range(n):
emails.append(input())

filtered_emails = filter_mail(emails)
filtered_emails.sort()
print(filtered_emails)```

Disclaimer: The above Problem (Validating Email Addresses With a Filter) is generated by Hacker Rank but the solution is Provided by CodingBroz. This tutorial is only for Educational and Learning Purpose.