["python","multithreading","dictionary","thread-safety"]
Thread Safety in Python's dictionary

I have a class which holds a dictionary class OrderBook: orders = {'Restaurant1': None, 'Restaurant2': None, 'Restaurant3': None, 'Restaurant4': None} @staticmethod def addOrder(restaurant_name, orders): OrderBook.orders[restaurant_name] = orders And I am running 4 threads (one for each restaurant) that call the method OrderBook.addOrder. Here is the function ran by each thread: def addOrders(restaurant_name): #creates orders ... OrderBook.addOrder(restaurant_name, orders) Is this safe, or do I have to use a lock before calling addOrder?
Python's built-in structures are thread-safe for single operations, but it can sometimes be hard to see where a statement really becomes multiple operations. Your code should be safe. Keep in mind: a lock here will add almost no overhead, and will give you peace of mind. https://web.archive.org/web/20201108091210/http://effbot.org/pyfaq/what-kinds-of-global-value-mutation-are-thread-safe.htm has more details.