Create An Email Validation Using Regular Expression in The Python Assignment Solution

Instructions

Objective

Write a python assignment program to create an email validation using regular expression.

Requirements and Specifications

Screenshot

Source Code

TASK 1 def factorial(n): # starting with value 1 result = 1 # keep multiplying by consecutive integers including n for i in range(n): result *= (i + 1) return result def main(): # keep asking user until nonnegative value is entered while True: n = int(input('Please input a nonnegative integer? ')) if n >= 0: # calculating factorial of given integer print('Factorial of', n, ':', factorial(n)) return else: # showing error message print('Please enter a nonnegative integer') print() if __name__ == '__main__': main() TASK 2 def factorial(n): # if n == 0, returning 1 if n == 0: return 1 # returning result as a product of (n-1)! and n return factorial(n-1) * n def main(): # keep asking user until nonnegative value is entered while True: n = int(input('Please input a nonnegative integer? ')) if n >= 0: # calculating factorial of given integer print('Factorial of', n, ':', factorial(n)) return else: # showing error message print('Please enter a nonnegative integer') print() if __name__ == '__main__': main() TASK 3 import re def check_email(email): # using following regex: # - positive number of symbols: alphanumeric/-/. # - single @ # - positive number of symbols: alphanumeric/-/. regex = '^[\w\-.]+[@][\w\-.]+$' if re.search(regex, email): # if email matches pattern, searching for index of '@' idx = email.index('@') # returning separated username and host, as a tuple return email[:idx], email[idx+1:] # if valid is not valid, returning None return None def main(): # keep asking user until value email is entered while True: result = check_email(input('Please input your email address:').strip()) if result: # outputting result of email parsing print('email: ', result[0] + '@' + result[1], ',', 'username: ', result[0], ',', 'host: ', result[1]) return else: # showing error message print('Not a valid email.') print() if __name__ == '__main__': main()