I am relatively new to Python and trying to implement a Multiprocessing module for my for loop.

I have an array of Image url's stored in img_urls which I need to download and apply some Google vision.

if __name__ == '__main__':

    img_urls = [ALL_MY_Image_URLS]
    runAll(img_urls)
    print("--- %s seconds ---" % (time.time() - start_time)) 

This is my runAll() method

def runAll(img_urls):
    num_cores = multiprocessing.cpu_count()

    print("Image URLS  {}",len(img_urls))
    if len(img_urls) > 2:
        numberOfImages = 0
    else:
        numberOfImages = 1

    start_timeProcess = time.time()

    pool = multiprocessing.Pool()
    pool.map(annotate,img_urls)
    end_timeProcess = time.time()
    print('\n Time to complete ', end_timeProcess-start_timeProcess)

    print(full_matching_pages)


def annotate(img_path):
    file =  requests.get(img_path).content
    print("file is",file)
    """Returns web annotations given the path to an image."""
    print('Process Working under ',os.getpid())
    image = types.Image(content=file)
    web_detection = vision_client.web_detection(image=image).web_detection
    report(web_detection)

I am getting this as the warning when I run it and python crashes

objc[67570]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called.
objc[67570]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
objc[67567]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called.
objc[67567]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
objc[67568]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called.
objc[67568]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
objc[67569]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called.
objc[67569]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
objc[67571]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called.
objc[67571]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
objc[67572]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called.
objc[67572]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.