# Python Data Structures ## `list` docs.python.org/3/tutorial/datastructures.html#more-on-lists - `list.extend(iterable)` method, appending all items in the iterable. ## [[heap|Heap]] - Example: [[merge-k-sorted-lists]] ## Counter - `Counter`, used to count hashable objects, e.g. `Counter("apple")`, which also has `most_common(k)` method built-in. - Examples: [[top-k-frequent-elements]], [[longest-repeating-character-replacement]] ## [[queue|Queue]] - Example: [[invert-bin-tree]], [[same-tree]]