Python data structure like dict

Question

Online I found some code that used the variable explored . This variable is implemented like a dictionary: explored = {rootId} , but it doesn't have key-value association, moreover this variabile uses the function .add(elem) while the dict doesn't have this function. eg. explored.add(elem) .

Which data structure is that? (I'm using python 3.6.3)

Answer 1

可能是一个集合，它具有方法“ add”，但是您可以简单地打印类型，例如：

print(type(explored))

Answer 2

It's a set . There are also online examples that use the methods you mentioned.

Next time you wonder, I suggest you just print the type, like this:

print(type(explored));

Answer 3

It's the set datastructure. Here's a link to it on the official docs: https://docs.python.org/3/tutorial/datastructures.html#sets