为什么这个变量会改变？
Why is this variable changing?
我正在和我的朋友一起编写一个国际象棋界面来取乐，最终我们都制作了机器人并与他们一决高下。当我重新评估寻找支票的合法动作时，我遇到了障碍，因为它们应该是非法动作。界面的实际代码有几千行，但我简化了代码以显示问题。我将 post 可以复制问题的简化代码，然后是我认为导致问题的关键部分。
简化代码：
class Pieces():
def __init__(self):
self.white_pawns_inf = [[0, 1, False, True], [1, 1, False, True], [2, 1, False, True], [3, 1, False, True], [4, 1, False, True], [5, 1, False, True], [6, 1, False, True], [7, 1, False, True]]
self.white_bishops_inf = [[2, 0, False], [5, 0, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.white_knights_inf = [[1, 0, False], [6, 0, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.white_rooks_inf = [[0, 0, False, True], [7, 0, False, True], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False]]
self.white_queens_inf = [[3, 0, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.white_king_inf = [[4, 0, True, True]]
self.black_pawns_inf = [[0, 6, True, True], [1, 6, True, True], [2, 6, True, True], [3, 6, True, True], [4, 6, True, True], [5, 6, True, True], [6, 6, True, True], [7, 6, True, True]]
self.black_bishops_inf = [[2, 2, True], [5, 7, True], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.black_knights_inf = [[6, 2, True], [6, 7, True], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.black_rooks_inf = [[0, 7, True, True], [7, 7, True, True], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False]]
self.black_queens_inf = [[3, 7, True], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.black_king_inf = [[4, 7, True, True]]
self.white_occupation_x = [0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7]
self.white_occupation_y = [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]
self.black_occupation_x = [0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7]
self.black_occupation_y = [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]
def check_checks(self):
take = True
for notation_val in ['a6', 'a5', 'b6', 'b5', 'c6', 'c5', 'd6', 'd5', 'e6', 'e5', 'f6', 'f5', 'g6', 'g5', 'h6', 'h5']:
#print(self.black_pawns_inf)
black_pawns = self.black_pawns_inf
#print(self.black_pawns_inf)
if True:
if True:
tox = notation.get_column_char(notation_val[-2])
toy = int(notation_val[-1]) - 1
if True:
fromx = tox
if True:
if toy == 4:
fromy = toy + 2
for i in range(0, 8):
if black_pawns[i][2] == True and black_pawns[i][0] == fromx and black_pawns[i][1] == toy + 1:
fromy = toy + 1
else:
fromy = toy + 1
if True:
for i in range(0, 8):
if black_pawns[i][2] == True and black_pawns[i][0] == fromx and black_pawns[i][1] == fromy:
print(self.black_pawns_inf)
black_pawns[i][0] = tox
black_pawns[i][1] = toy
black_pawns[i][3] = False
print(self.black_pawns_inf)
class Notation():
def __init__(self):
pass
def get_column(self, x):
if x == 0:
return "a"
elif x == 1:
return "b"
elif x == 2:
return "c"
elif x == 3:
return "d"
elif x == 4:
return "e"
elif x == 5:
return "f"
elif x == 6:
return "g"
elif x == 7:
return "h"
def get_column_char(self, x):
if x == "a":
return 0
elif x == "b":
return 1
elif x == "c":
return 2
elif x == "d":
return 3
elif x == "e":
return 4
elif x == "f":
return 5
elif x == "g":
return 6
elif x == "h":
return 7
def get_row(self, y):
for i in range(0, 8):
if y == i:
return str(i + 1)
if y != 0 and y != 1 and y != 2 and y != 3 and y != 4 and y != 5 and y != 6 and y != 7:
return "9"
white_turn = False
pieces = Pieces()
notation = Notation()
#print(pieces.black_pawns_inf)
pieces.check_checks()
#print(pieces.black_pawns_inf)
关键部分是：
print(self.black_pawns_inf)
black_pawns[i][0] = tox
black_pawns[i][1] = toy
black_pawns[i][3] = False
print(self.black_pawns_inf)
和
black_pawns = self.black_pawns_inf
问题是，变量“self.black_pawns_inf”在函数中发生了变化，它出现一次（不包括打印语句），其中设置了 black_pawns。这个变量改变对我来说毫无意义。如上所示，变量更改的隔离代码区域位于第一个关键部分。我在之前和之后打印变量，它发生了变化，即使据称改变它的 3 行代码甚至不包括这个变量！！！我假设我在 python 中遗漏了一些东西，它在相互设置的变量之间创建了一个 link 并且以某种方式通过改变一个，它也改变了另一个。下面我将显示当程序为 运行 for notation_val in ['a6', 'a5', 'b6', [=29] 的第一次迭代时的输出=], 'c6', 'c5', 'd6', 'd5', 'e6', 'e5', 'f6', 'f5' , 'g6', 'g5', 'h6', 'h5']:" 其中变化发生:
[[0, 6, True, True], [1, 6, True, True], [2, 6, True, True], [3, 6, True, True], [4, 6, True, True], [5, 6, True, True], [6, 6, True, True], [7, 6, True, True]]
[[0, 5, True, False], [1, 6, True, True], [2, 6, True, True], [3, 6, True, True], [4, 6, True, True], [5, 6, True, True], [6, 6, True, True], [7, 6, True, True]]
如您所见，每个列表中的第一个列表发生变化 - 6 变为 5，True 变为 False - 这对于变量“black_pawns”是预期的，但对于变量“[=42”也会发生=]"...
我已尽力解释问题，如有任何帮助，我们将不胜感激，谢谢！
I assume I am missing something in python that it creates a link between variables that are set to each other and somehow by changing one, it also changes the other.
你是对的 - Python 中的某些类型（例如 list 是 可变的 并且会显示此行为。 ints 和 strs 等其他类型是 immutable 并且没有这种行为。请参阅有关此主题的 previous answer 以获取解释。
您可以复制 self.black_pawns_inf 以避免就地修改。在您的情况下，您有一个列表列表，因此您需要进行深拷贝以避免就地修改它：
from copy import deepcopy
black_pawns = deepcopy(self.black_pawns_inf)
然后您将能够修改 black_pawns 的元素，而无需修改 self.black_pawns_inf 的元素。
我正在和我的朋友一起编写一个国际象棋界面来取乐，最终我们都制作了机器人并与他们一决高下。当我重新评估寻找支票的合法动作时，我遇到了障碍，因为它们应该是非法动作。界面的实际代码有几千行，但我简化了代码以显示问题。我将 post 可以复制问题的简化代码，然后是我认为导致问题的关键部分。 简化代码：
class Pieces():
def __init__(self):
self.white_pawns_inf = [[0, 1, False, True], [1, 1, False, True], [2, 1, False, True], [3, 1, False, True], [4, 1, False, True], [5, 1, False, True], [6, 1, False, True], [7, 1, False, True]]
self.white_bishops_inf = [[2, 0, False], [5, 0, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.white_knights_inf = [[1, 0, False], [6, 0, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.white_rooks_inf = [[0, 0, False, True], [7, 0, False, True], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False]]
self.white_queens_inf = [[3, 0, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.white_king_inf = [[4, 0, True, True]]
self.black_pawns_inf = [[0, 6, True, True], [1, 6, True, True], [2, 6, True, True], [3, 6, True, True], [4, 6, True, True], [5, 6, True, True], [6, 6, True, True], [7, 6, True, True]]
self.black_bishops_inf = [[2, 2, True], [5, 7, True], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.black_knights_inf = [[6, 2, True], [6, 7, True], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.black_rooks_inf = [[0, 7, True, True], [7, 7, True, True], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False], [0, 7, False, False]]
self.black_queens_inf = [[3, 7, True], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False], [0, 7, False]]
self.black_king_inf = [[4, 7, True, True]]
self.white_occupation_x = [0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7]
self.white_occupation_y = [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]
self.black_occupation_x = [0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7]
self.black_occupation_y = [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1]
def check_checks(self):
take = True
for notation_val in ['a6', 'a5', 'b6', 'b5', 'c6', 'c5', 'd6', 'd5', 'e6', 'e5', 'f6', 'f5', 'g6', 'g5', 'h6', 'h5']:
#print(self.black_pawns_inf)
black_pawns = self.black_pawns_inf
#print(self.black_pawns_inf)
if True:
if True:
tox = notation.get_column_char(notation_val[-2])
toy = int(notation_val[-1]) - 1
if True:
fromx = tox
if True:
if toy == 4:
fromy = toy + 2
for i in range(0, 8):
if black_pawns[i][2] == True and black_pawns[i][0] == fromx and black_pawns[i][1] == toy + 1:
fromy = toy + 1
else:
fromy = toy + 1
if True:
for i in range(0, 8):
if black_pawns[i][2] == True and black_pawns[i][0] == fromx and black_pawns[i][1] == fromy:
print(self.black_pawns_inf)
black_pawns[i][0] = tox
black_pawns[i][1] = toy
black_pawns[i][3] = False
print(self.black_pawns_inf)
class Notation():
def __init__(self):
pass
def get_column(self, x):
if x == 0:
return "a"
elif x == 1:
return "b"
elif x == 2:
return "c"
elif x == 3:
return "d"
elif x == 4:
return "e"
elif x == 5:
return "f"
elif x == 6:
return "g"
elif x == 7:
return "h"
def get_column_char(self, x):
if x == "a":
return 0
elif x == "b":
return 1
elif x == "c":
return 2
elif x == "d":
return 3
elif x == "e":
return 4
elif x == "f":
return 5
elif x == "g":
return 6
elif x == "h":
return 7
def get_row(self, y):
for i in range(0, 8):
if y == i:
return str(i + 1)
if y != 0 and y != 1 and y != 2 and y != 3 and y != 4 and y != 5 and y != 6 and y != 7:
return "9"
white_turn = False
pieces = Pieces()
notation = Notation()
#print(pieces.black_pawns_inf)
pieces.check_checks()
#print(pieces.black_pawns_inf)
关键部分是：
print(self.black_pawns_inf)
black_pawns[i][0] = tox
black_pawns[i][1] = toy
black_pawns[i][3] = False
print(self.black_pawns_inf)
和
black_pawns = self.black_pawns_inf
问题是，变量“self.black_pawns_inf”在函数中发生了变化，它出现一次（不包括打印语句），其中设置了 black_pawns。这个变量改变对我来说毫无意义。如上所示，变量更改的隔离代码区域位于第一个关键部分。我在之前和之后打印变量，它发生了变化，即使据称改变它的 3 行代码甚至不包括这个变量！！！我假设我在 python 中遗漏了一些东西，它在相互设置的变量之间创建了一个 link 并且以某种方式通过改变一个，它也改变了另一个。下面我将显示当程序为 运行 for notation_val in ['a6', 'a5', 'b6', [=29] 的第一次迭代时的输出=], 'c6', 'c5', 'd6', 'd5', 'e6', 'e5', 'f6', 'f5' , 'g6', 'g5', 'h6', 'h5']:" 其中变化发生:
[[0, 6, True, True], [1, 6, True, True], [2, 6, True, True], [3, 6, True, True], [4, 6, True, True], [5, 6, True, True], [6, 6, True, True], [7, 6, True, True]]
[[0, 5, True, False], [1, 6, True, True], [2, 6, True, True], [3, 6, True, True], [4, 6, True, True], [5, 6, True, True], [6, 6, True, True], [7, 6, True, True]]
如您所见，每个列表中的第一个列表发生变化 - 6 变为 5，True 变为 False - 这对于变量“black_pawns”是预期的，但对于变量“[=42”也会发生=]"...
我已尽力解释问题，如有任何帮助，我们将不胜感激，谢谢！
I assume I am missing something in python that it creates a link between variables that are set to each other and somehow by changing one, it also changes the other.
你是对的 - Python 中的某些类型（例如 list 是 可变的 并且会显示此行为。 ints 和 strs 等其他类型是 immutable 并且没有这种行为。请参阅有关此主题的 previous answer 以获取解释。
您可以复制 self.black_pawns_inf 以避免就地修改。在您的情况下，您有一个列表列表，因此您需要进行深拷贝以避免就地修改它：
from copy import deepcopy
black_pawns = deepcopy(self.black_pawns_inf)
然后您将能够修改 black_pawns 的元素，而无需修改 self.black_pawns_inf 的元素。