Design File System Python Solution with Tests

lcpy gen -n 1166   # by problem number
lcpy gen -s design_file_system   # by problem name

Input:
["FileSystem","createPath","get"]
[[],["/a",1],["/a"]]
Output:
[null,true,1]
Explanation:
FileSystem fileSystem = new FileSystem();

fileSystem.createPath("/a", 1); // return true
fileSystem.get("/a"); // return 1

Input:
["FileSystem","createPath","createPath","get","createPath","get"]
[[],["/leet",1],["/leet/code",2],["/leet/code"],["/c/d",1],["/c"]]
Output:
[null,true,true,2,false,-1]
Explanation:
FileSystem fileSystem = new FileSystem();

fileSystem.createPath("/leet", 1); // return true
fileSystem.createPath("/leet/code", 2); // return true
fileSystem.get("/leet/code"); // return 2
fileSystem.createPath("/c/d", 1); // return false because the parent path "/c" doesn't exist.
fileSystem.get("/c"); // return -1 because this path doesn't exist.

class FileSystem:
    # Time: create_path O(n), get O(n), where n is the number of path segments
    # Space: O(total number of segments across created paths)
    def __init__(self) -> None:
        self.paths: dict[str, int] = {}

    def create_path(self, path: str, value: int) -> bool:
        if path in self.paths:
            return False
        parent = path.rsplit("/", 1)[0]
        if parent and parent not in self.paths:
            return False
        self.paths[path] = value
        return True

    def get(self, path: str) -> int:
        return self.paths.get(path, -1)