These are some resources on how to use the collections Python package.
from collections import defaultdict counter = defaultdict(int) counter["sheep"] += 1 print(counter["sheep"]) # 1 print(counter["dog"]) # 0
Will allow builtin methods based on the default type.
defaultdict(int) will allow a
+= 1 on any key and it will be defined immediately if doesn't exist;
(set) will allow
.add(value) to a set and will create it if none exists, etc.
from collections import deque cards = [1,2,3,4] deck = deque(cards) top_card = deck.popleft() deck.append(top_card) # cards == [2,3,4,1]
If you need a copy of the deque, you will need to import the
copy.deepcopy method, as slices don't work. If you need to slice, you can use
Note that if you are looking for a queue, you can use a standard list as a queue by using
list.append(item). It is much faster and requires no imports.
Last modified: 202107181935