class data_reader():
def __init__(self,paths_list,queue_limit = 1,parallel = True):
    print 'data reader constructor'
    self.paths = paths_list
    self.count = len(paths_list)
    self.async = async
    self.dict = {};
    self.lock = multiprocessing.Lock()
    self.queue = multiprocessing.Queue(queue_limit)
    if parallel:
        self.child = multiprocessing.Process(target = self.load_paths,args = (self.paths,self.queue,))
        self.child.daemon = True
        self.child.start()
        print 'child started'
    else:
        self.load_paths(self.paths,self.queue)

def get_next():
        return self.queue.get()

data_train = data_reader(train_paths_list)
data_valid = data_reader(valid_paths_list)
data_test = data_reader(test_paths_list)

'data reader constructor'