init

Tutorium/tut09/src/my_collections.py

@@ -0,0 +1,56 @@
+from dataclasses import dataclass, InitVar
+
+
+@dataclass
+class MyList[T]:
+    _internal_list: InitVar[list[T]]
+    _length: InitVar[int]
+
+    def __init__(self) -> None:
+        self.__internal_list: list[T] = []
+        self.__length = 0
+
+    def add(self, item: T) -> None:
+        self.__internal_list += [item]
+        self.__length += 1
+
+    @property
+    def length(self) -> int:
+        return self.__length
+
+
+@dataclass
+class GameObject:
+    _position: InitVar[tuple[int, int]]
+
+    def __post_init__(self, position: tuple[int, int]) -> None:
+        assert (0, 0) <= position
+        self.__position = position
+
+    @property
+    def position(self) -> tuple[int, int]:
+        return self.__position
+
+    @position.setter
+    def position(self, position: tuple[int, int]) -> None:
+        if (0, 0) > position:
+            return
+        self.__position = position
+
+
+if __name__ == "__main__":
+    xs: MyList[int] = MyList()
+    xs.add(100)
+    assert xs.length == 1
+    position: tuple[int, int] = (0, 0)
+    my_obj = GameObject(position)
+    assert my_obj.position == (0, 0)
+    try:
+        GameObject((0, -1))
+    except AssertionError:
+        pass
+    else:
+        raise AssertionError(
+            f"{my_obj} should have thrown a assertation error")
+    my_obj.position = (-1, 0)
+    assert my_obj.position == (0, 0)