Python: is thread still running

Question

How do I see whether a thread has completed? I tried the following, but threads_list does not contain the thread that was started, even when I know the thread is still running.

import thread import threading  id1 = thread.start_new_thread(my_function, ()) #wait some time threads_list = threading.enumerate() # Want to know if my_function() that was called by thread id1 has returned   def my_function()     #do stuff     return 

Answer 1

The key is to start the thread using threading, not thread:

t1 = threading.Thread(target=my_function, args=()) t1.start() 

Then use

z = t1.is_alive() # Changed from t1.isAlive() based on comment. I guess it would depend on your version. 

or

l = threading.enumerate() 

You can also use join():

t1 = threading.Thread(target=my_function, args=()) t1.start() t1.join() # Will only get to here once t1 has returned. 

Answer 2

You must start the thread by using threading.

id1 = threading.Thread(target = my_function) id1.start() 

And as of above if you don't have any args to mention you can just leave it blank.

To check your thread is alive or not you can use is_alive()

if id1.is_alive():    print("Is Alive") else:    print("Dead") 

Note: isAlive() is deprecated instead use is_alive()as per the python docs.

Python Documentation