Validating phone numbers

Let’s dive into the interesting topic of regular expressions! You are given some input, and you are required to check whether they are valid mobile numbers.

A valid mobile number is a ten digit number starting with a 7, 8 or 9.

Concept

A valid mobile number is a ten digit number starting with a 7, 8 or 9.

Regular expressions are a key concept in any programming language. A quick explanation with Python examples is available here. You could also go through the link below to read more about regular expressions in Python.

https://developers.google.com/edu/python/regular-expressions

Input Format

The first line contains an integer N, the number of inputs.
N lines follow, each containing some string.

Constraints

1 ≤ N ≤ 10

2 ≤ len(Number) ≤ 15

Output Format

For every string listed, print “YES” if it is a valid mobile number and “NO” if it is not on separate lines. Do not print the quotes.

Sample Input

2
9587456281
1252478965

Sample Output

YES
NO

Solution Implementation

import re
N = int(input())
for i in range(0, N):
    # Must start with a 7, 8, or 9 according to the problem, must only contain 10 digits total
    print('YES') if re.match(r'[789]\d{9}$', input()) else print('NO')