Run Class methods in threads (python)

You can inherit Thread class in DomainOperation, in this way code would be more clean and easily understandable. you have to override a run() method.

from threading import Thread

class DomainOperations(Thread):
    def __init__(self, *args, **kwargs):
       super().__init__(*args, **kwargs)
       self.domain_ip = ''
       self.website_thumbnail = ''

   def resolve_domain(self):
       self.domain_ip = 'foo'

   def generate_website_thumbnail(self):
       self.website_thumbnail= 'bar'

   def run(self):
       #domain will be resolved on first thread
       self.resolve_domain()
       #thumbnail will be resolved on second OR newly created below thread
       thread2 = Thread(target=self.generate_website_thumbnail)
       thread.start()
       # thread1 will wait for thread2
       self.join()
       # thread2 will wait for thread1, if it's late.
       thread2.join()
       # here it will print ip and thumbnail before exiting first thread
       print(self.domain_ip, self.website_thumbnail)

And you will start your threads in this way.

if __name__ == '__main__':
   thread1 = DomainOperations()
   thread1.start()

If you call them from the class, it is as simple as:

import threading

class DomainOperations:

    def __init__(self):
        self.domain_ip = ''
        self.website_thumbnail = ''

    def resolve_domain(self):
        self.domain_ip = 'foo'

    def generate_website_thumbnail(self):
        self.website_thumbnail= 'bar'

    def run(self):
        t1 = threading.Thread(target=self.resolve_domain)
        t2 = threading.Thread(target=self.generate_website_thumbnail)
        t1.start()
        t2.start()
        t1.join()
        t2.join()
        print(self.domain_ip, self.website_thumbnail)

if __name__ == '__main__':
    d = DomainOperations()
    d.run()