Can python threads access variables in the namespace?

Question

I have a script that creates a bunch of threads, runs a program to use the threads to run tasks from a queue, and returns something from each thread. I want to count how many of

Answer 1

The problem happens because a variable that is assigned inside a function is considered to be local to that function. If you want to modify the value of a variable successfull, that is created outside a foo, you need to explicitly inform the interpreter that you are going to work with a global variable inside a function. This can be done in the following way:

def foo():
    global successfull
    while True:
        task=q.get()
        #do some work
        print task
        successful+=1 # triggers an error
        q.task_done()

Now the code should work as expected.