from __future__ import annotations # for Class forward reference
import random
import uuid
from typing import ClassVar
[docs]
class Node:
"""
Should be subclassed only
"""
# Class Var for statistics
deepest_level: ClassVar[int] = 0
largest_sibling_number: ClassVar[int] = 0
all_nodes: ClassVar[list[Node]] = []
def __init_subclass__(cls):
""" each subclass must define its own ClassVar """
# TODO to be renamed for clarity
super().__init_subclass__()
cls.deepest_level: ClassVar[int] = 0
cls.largest_sibling_number: ClassVar[int] = 0
cls.all_nodes: ClassVar[list[Node]] = []
return cls
def __new__(cls, name: str, parent: Node | None = None) -> None:
"""
prevent the user to set the same name for 2 nodes
??? better to do it with uuid?
"""
for n in cls.all_nodes:
if name == n.name:
raise AttributeError('Node with this name already exists')
else:
return super().__new__(cls)
def __init__(self, name: str, parent: Node | None = None) -> None:
self.name = name
self.parent = parent # is set with add_child
self.children: list[Node] = []
self.id = uuid.uuid4()
type(self).all_nodes.append(self)
[docs]
def add_child(self, child: Node) -> None:
"""
Add new child node to current instance
:param child: Node object
"""
child.parent = self
if child.name not in [c.name for c in self.children]:
self.children.append(child)
if child.level > type(self).deepest_level:
type(self).deepest_level = child.level
if len(self.children) > type(self).largest_sibling_number:
type(self).largest_sibling_number = len(self.children)
else:
raise Exception('Child with same name already exists')
@property
def siblings(self) -> list[Node]:
""" returns all the siblings of the Node object """
if self.has_siblings():
return self.parent.children
@property
def parents(self) -> list[Node]:
""" returns all the ancestors of the Node object """
parents = []
p = self
while p.has_parent():
p = p.parent
parents.append(p)
return parents
@property
def level(self) -> int:
""" returns the level of the Node object """
level = 0
p = self
while p.has_parent():
level += 1
p = p.parent
return level
@property
def path(self) -> str:
"""
returns a representation of the ancestor lineage of self
"""
path = ''
for p in reversed(self.parents):
path += p.name+'.'
path += self.name
return path
[docs]
def is_sibling(self, other: str) -> bool:
"""
Check if Node object is a sibling of the other Node object
:param other: Other Node object to be compared with
"""
if other in [s.name for s in self.siblings]:
return True
else:
return False
[docs]
def is_child(self, other: str) -> bool:
""" check if Node object is a child of the other Node object """
if other in [s.name for s in self.children]:
return True
else:
return False
[docs]
def pretty_print(self, option: str = 'default') -> None:
""" print children tree from current instance """
dashes = ' '*self.level+'|'+'--'*self.level+' '
if option == 'id':
dashes += f'[{self.id}] '
print(f'{dashes}{self.name}')
for c in self.children:
c.pretty_print(option)
[docs]
def has_parent(self) -> bool:
""" check if Node object has a parent or not """
if self.parent is not None:
return True
return False
[docs]
def has_children(self) -> bool:
""" check if Node object has one child at least """
if self.children is not None:
return True
return False
[docs]
def has_siblings(self) -> bool:
""" check if Node object has one sibling at least """
if self.has_parent() and self.parent.has_children() \
and len(self.parent.children) > 0:
return True
return False
[docs]
def get_child(self, name: str) -> Node | None:
""" find and returns a child with specified name. None if nothing found """
for c in self.children:
if c.name == name:
return c
return None
[docs]
def get_sibling(self, name: str) -> Node | None:
""" find and returns a sibling with specified name. None if nothing
found """
for c in self.siblings:
if c.name == name:
return c
return None
def get_children(self, name: str) -> list[Node]:
# refactoring, recursion is not good
results = []
if self.name == name:
results.append(self)
for c in self.children:
results += c.get_children(name)
return results
[docs]
@staticmethod
def check_lineage(nodes: list[Node]) -> bool:
"""
check if the list of nodes is a straight lineage:
node 1 (ancestor) -> node 2 -> node 3 -> ... -> node n (grand
children)
"""
for i in range(1, len(nodes)):
if nodes[i].parent != nodes[i-1]:
return False
return True
[docs]
@classmethod
def reset_stats(cls) -> None:
"""
reset all the ClassVar members
"""
cls.deepest_level = 0
cls.largest_sibling_number = 0
cls.all_nodes = []
[docs]
@classmethod
def create_random_nodes(cls, type_: str = 'cmd', depth: int = 0) -> Node:
"""
Creates random tree of nodes for testing purpose
"""
def create_node(level, i):
id_ = len(cls.all_nodes) + 1
return cls(f'{type_}_'+str(id_))
def create_node_list(level: int, width: int = 5):
return [create_node(level, i)
for i in range(random.randint(1, width))]
def create_arg_tree(arg: cls):
if arg.level < depth:
for a in create_node_list(arg.level):
arg.add_child(a)
create_arg_tree(a)
return arg
arg = cls('parser')
return create_arg_tree(arg)
def __lt__(self, other):
return self.level < other.level
def __gt__(self, other):
return self.level > other.level
def __le__(self, other):
return self.level <= other.level
def __ge__(self, other):
return self.level >= other.level
def __str__(self) -> str:
return self.name
if __name__ == "__main__":
# while True:
# master_node = Node.create_random_nodes(depth=3, type_='cmd')
# node_list = [master_node, master_node.children[0],
# master_node.children[0].children[0]]
# random.shuffle(node_list)
# print([n.name for n in node_list])
# print(Node.check_lineage(node_list))
# input('pause')
class Person(Node):
pass
bob = Person('Bob')
eve = Person('Eve')
alice = Person('Alice')
# Alice is parent of bob and eve
alice.add_child(bob)
alice.add_child(eve)
alice.pretty_print(option = 'id')
print(alice.id)