Creating an empty deque in Python with a max length?

问题

I'm looking at the documentation for a Python deque, and it looks like the constructor is deque([iterable[, maxlen]]). Is there no way to make an empty deque (that is, without specifying the iterable) with a max length?

回答1:

You could provide a list literal directly, so you don't have to declare anything on a separate line:

>>> collections.deque([], 42)
deque([], maxlen=42)

You could also provide maxlen as a named argument:

>>> collections.deque(maxlen=23)
deque([], maxlen=23)

来源：https://stackoverflow.com/questions/26124816/creating-an-empty-deque-in-python-with-a-max-length