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.

Validating Email Addresses With a Filter


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.

Valid email addresses must follow these rules:

  • 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.


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))


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

  • string s: the string to test


  • 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.


Each line is a non-empty string.

Sample Input

[email protected]
[email protected]
[email protected]

Sample Output

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

Solution – Validating Email Addresses With a Filter

def fun(email):
        username, url = email.split('@')
        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
        return True

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

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

filtered_emails = filter_mail(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.

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