没有通过蟒树的期望值

Question

我找不到可用于创建国际象棋开头树形结构的蟒蛇树，所以我试图写我自己的。为了进一步深入树中，我尝试在添加新位置时返回一个子根，但似乎所有位置都已添加到根，并且没有像我期望的那样给出对某个子根的引用，尽管我做检查，根也有很多孙子。因为你已经滥用class variables.

基本上，当你声明children外面在类级别范围的任何功能，并且所有Node对象共享同一个列表

import chess.pgn 

class Node(object): 
    children = [] 
    score = None 
    def __init__(self, fen): 
     self.fen = fen 
    def add(self, fen): 
     for c in self.children: 
      if c.fen == (fen): 
       print("working") 
       return c 
     self.children.append(Node(fen)) 
     return self.children[-1] 

root = Node('rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1') 
def createTree(fileName): 
    pgn = open(fileName) 
    game = chess.pgn.read_game(pgn) 
    while(game):  
     next_move = game.variations[0] 
     fen = next_move.board().fen() 
     global root 
     currentRoot = root.add(fen) 

     while(not next_move.is_end() and next_move.board().fullmove_number <= 5): 
      next_move = next_move.variations[0] 
      fen = next_move.board().fen() 
      currentRoot = currentRoot.add(fen) 
      print(currentRoot.children) 
     game = chess.pgn.read_game(pgn) 

file = r"C:\all.pgn" 
createTree(file) 
for n in root.children: 
    print(n.fen) 

Answer 1

你的代码失败。您希望在__init__中将其定义为self.children，以便它在实例级别进行作用域。

class Node: 
    def __init__(self, fen): 
     self.fen = fen 
     self.score = None 
     self.children = [] 
    ...