[Sync Iteration] python/pov/2

solutions/python/pov/2/pov.py

@@ -0,0 +1,80 @@
+from json import dumps
+from functools import cache
+from typing import Any
+
+
+class Tree:
+    def __init__(self, label, children=None):
+        self.label = label
+        self.children = children if children is not None else []
+
+    def __dict__(self):
+        return {self.label: [c.__dict__() for c in sorted(self.children)]}
+
+    def __str__(self, indent=None):
+        return dumps(self.__dict__(), indent=indent)
+
+    def __lt__(self, other):
+        return self.label < other.label
+
+    def __eq__(self, other):
+        equal = self.label == other.label
+        equal_children = all([child in other.children for child in self.children])
+        equal_other_children = all([child in self.children for child in other.children])
+        return equal and equal_children and equal_other_children
+
+    def __getitem__(self, item):
+        if item == self.label:
+            return self
+        for child in self.children:
+            return child[item]
+        raise IndexError(f"Label {item} not found in {self}")
+
+    def nodes_from_root(self, label:str) -> list | None:
+        if label == self.label:
+            return [self,]
+        else:
+            paths = [path for child in self.children if (path := child.nodes_from_root(label))]
+            if 0 < len(paths):
+                path = paths[0]
+                path.insert(0, self)
+                return path
+        return None
+
+    def from_pov(self, from_node:str):
+        if self.label == from_node:
+            return self
+        path:list = self.nodes_from_root(from_node)
+        if not path:
+            # when a tree cannot be oriented to a new node POV
+            raise ValueError(f"Tree could not be reoriented")
+        tree:Tree = path[-1]
+        prior_node = tree
+        for node in path[-2::-1]:
+            prior_node.children.append(node)
+            if prior_node not in node.children:
+                pass
+            node.children.remove(prior_node)
+            prior_node = node
+        return tree
+
+    def path_from_root(self, label:str) -> list[str] | None:
+        path = self.nodes_from_root(label)
+        if not path:
+            return path
+        return [node.label for node in path]
+
+    def path_to(self, from_node, to_node):
+        from_path = self.path_from_root(from_node)
+        to_path = self.path_from_root(to_node)
+        if not to_path:
+            # when a path cannot be found between root and destination nodes on the tree.
+            raise ValueError("No path found")
+        if not from_path:
+            # when a path cannot be found between root and start nodes on the tree.
+            raise ValueError("Tree could not be reoriented")
+        while 0 < len(from_path) and 0 < len(to_path) and from_path[0] == to_path[0]:
+            nexus = [from_path[0]]
+            from_path = from_path[1:]
+            to_path = to_path[1:]
+        return from_path[::-1] + nexus + to_path