class SWE:
  def __init__(self, name: str, interests: [str], working_on: [str]) -> None:
    self.name = name
    self.interests = interests
    self.working_on = working_on
    
  def say_hi(self) -> None:
    print(self)
    
  def __str__(self):
    return 'Hey! I\'m {}, a Software Engineer. I\'m interested in {} and I\'m currently working on {}.' \
             .format(self.name, ', '.join(self.interests), ', '.join(self.working_on))
             
saud = SWE('Saud', ['AI', 'System softwares', 'Competitive Programming'], ['XR based DApp'])
saud.say_hi() 
# Hey! I'm Saud, a Software Engineer. I'm interested in AI, System softwares, Competitive Programming and I'm currently working on XR based DApp.