# Validating Email Addresses With a Filter Hackerrank solution

## Validating Email Addresses With a Filter Hackerrank Solution

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 username@websitename.extension 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  to  (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))
```

Easy, isn’t it?

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
brian-23@hackerrank.com
britts_54@hackerrank.com
```

Sample Output

`['brian-23@hackerrank.com', 'britts_54@hackerrank.com', 'lara@hackerrank.com']`

Code:

```
import re
def fun(s):

pt=re.compile("([a-zA-Z0-9_-]+)@([a-zA-Z0-9]+)\.([a-zA-z]{1,3})\$")
return pt.match(s)

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

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

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

```

Disclaimer: This problem is originally created and published by HackerRank, we only provide solutions to this problem. Hence, doesn’t guarantee the truthfulness of the problem. This is only for information purposes.