Design HashMap Python Solution with Tests

lcpy gen -n 706   # by problem number
lcpy gen -s design_hash_map   # by problem name

Input
["MyHashMap", "put", "put", "get", "get", "put", "get", "remove", "get"]
[[], [1, 1], [2, 2], [1], [3], [2, 1], [2], [2], [2]]
Output
[null, null, null, 1, -1, null, 1, null, -1]

Explanation
MyHashMap myHashMap = new MyHashMap();
myHashMap.put(1, 1); // The map is now [[1,1]]
myHashMap.put(2, 2); // The map is now [[1,1], [2,2]]
myHashMap.get(1);    // return 1
myHashMap.get(3);    // return -1 (not found)
myHashMap.put(2, 1); // The map is now [[1,1], [2,1]] (update)
myHashMap.get(2);    // return 1
myHashMap.remove(2); // remove the mapping for 2, The map is now [[1,1]]
myHashMap.get(2);    // return -1 (not found)

class MyHashMap:
    # Time: O(n) init, O(1) ops
    # Space: O(n)
    def __init__(self) -> None:
        # Problem guarantees 0 <= key, value <= 10^6; -1 marks "no mapping".
        self._values: list[int] = [-1] * 1_000_001

    # Time: O(1)
    # Space: O(1)
    def put(self, key: int, value: int) -> None:
        self._values[key] = value

    # Time: O(1)
    # Space: O(1)
    def get(self, key: int) -> int:
        return self._values[key]

    # Time: O(1)
    # Space: O(1)
    def remove(self, key: int) -> None:
        self._values[key] = -1