Make 2 functions run at the same time
The answer about threading is good, but you need to be a bit more specific about what you want to do.
If you have two functions that both use a lot of CPU, threading (in CPython) will probably get you nowhere. Then you might want to have a look at the multiprocessing module or possibly you might want to use jython/IronPython.
If CPU-bound performance is the reason, you could even implement things in (non-threaded) C and get a much bigger speedup than doing two parallel things in python.
Without more information, it isn't easy to come up with a good answer.
Do this:
from threading import Thread
def func1():
print('Working')
def func2():
print("Working")
if __name__ == '__main__':
Thread(target = func1).start()
Thread(target = func2).start()