在两个线程之间求和列表的元素

Question

I'm trying to add the elements of a list in a dictionary:

if threading.current_thread().name == "Thread 1":
    print("I'm thread 1")
    for word in list_thread1:
        if word[0] in shared_dict:
            shared_dict[word[0]].append(1)
        else:
            shared_dict[word[0]] = [1]

if threading.current_thread().name == "Thread 2":
    print("I'm thread 2")
    for word in list_thread2:
        if word[0] in shared_dict:
            shared_dict[word[0]].append(1)
        else:
            shared_dict[word[0]] = [1]

I'm looping over the list and I look if the key is already on the dictionary, if the key exists, I append the number 1, if the key does not exists, I create the list [1]. But the problem I'm having is this error (only in when I use 2 threads):

    shared_dict[word[0]].append(1)
AttributeError: 'int' object has no attribute 'append'

and I don't know why. Can you explain what I'm doing bad? Thanks

Answer 1

The problem that I've discovered was about not joining the threads, so the thread continued execution and creating dataraces with the other thread