python中的实例变量，受另一个实例的值影响

Question

class State:
'defines the state of the class'
_state = []
"""pawn = 1     rook = 2    knight = 3    bishop = 4    queen = 5    king = 6    none = 7    whiteSq = 0    blackSq = 1    whiteCol = 0    blackCol = 1"""
def __init__( self, value ):
    'constructor call with value 0 to load intial pos, and with 1 to load blank board'
    if(value == 1):
        for i in range(8):
            self._state.append([])
            for j in range(8):
                self._state[i].append([])
                self._state[i][j].append( (i+j)%2 , 7 , 7 )
    elif(value == 0):
        for i in range(8):
            self._state.append([])
            if(i==0):
                self._state[i].append( [ 0 , 1 , 2] )
                self._state[i].append( [ 1 , 1 , 3] )
                self._state[i].append( [ 0 , 1 , 4] )
                self._state[i].append( [ 1 , 1 , 5] )
                self._state[i].append( [ 0 , 1 , 6] )
                self._state[i].append( [ 1 , 1 , 4] )
                self._state[i].append( [ 0 , 1 , 3] )
                self._state[i].append( [ 1 , 1 , 2] )
            elif(i==1):
                for j in range(8):
                    self._state[i].append( [(i+j)%2 , 1 , 1] )
            elif(i==6):
                for j in range(8):
                    self._state[i].append( [(i+j)%2 , 0 , 1] )
            elif(i==7):
                self._state[i].append( [ 1 , 0 , 2] )
                self._state[i].append( [ 0 , 0 , 3] )
                self._state[i].append( [ 1 , 0 , 4] )
                self._state[i].append( [ 0 , 0 , 5] )
                self._state[i].append( [ 1 , 0 , 6] )
                self._state[i].append( [ 0 , 0 , 4] )
                self._state[i].append( [ 1 , 0 , 3] )
                self._state[i].append( [ 0 , 0 , 2] )
            else:
                for j in range(8):
                    self._state[i].append( [(i+j)%2 , 7 , 7] )  
def printState(self):
    for i in range(8):
        print( self._state[i] )

我看不懂这个输出

c=State(0);c.printState()
[[0, 1, 2], [1, 1, 3], [0, 1, 4], [1, 1, 5], [0, 1, 6], [1, 1, 4], [0, 1, 3], [1, 1, 2]]
[[1, 1, 1], [0, 1, 1], [1, 1, 1], [0, 1, 1], [1, 1, 1], [0, 1, 1], [1, 1, 1], [0, 1, 1]]
[[0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7]]
[[1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7]]
[[0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7]]
[[1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7]]
[[0, 0, 1], [1, 0, 1], [0, 0, 1], [1, 0, 1], [0, 0, 1], [1, 0, 1], [0, 0, 1], [1, 0, 1]]
[[1, 0, 2], [0, 0, 3], [1, 0, 4], [0, 0, 5], [1, 0, 6], [0, 0, 4], [1, 0, 3], [0, 0, 2]]
>>> a=State(0);a.printState()
[[0, 1, 2], [1, 1, 3], [0, 1, 4], [1, 1, 5], [0, 1, 6], [1, 1, 4], [0, 1, 3], [1, 1, 2], [0, 1, 2], [1, 1, 3], [0, 1, 4], [1, 1, 5], [0, 1, 6], [1, 1, 4], [0, 1, 3], [1, 1, 2]]
[[1, 1, 1], [0, 1, 1], [1, 1, 1], [0, 1, 1], [1, 1, 1], [0, 1, 1], [1, 1, 1], [0, 1, 1], [1, 1, 1], [0, 1, 1], [1, 1, 1], [0, 1, 1], [1, 1, 1], [0, 1, 1], [1, 1, 1], [0, 1, 1]]
[[0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7]]
[[1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7]]
[[0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7]]
[[1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7], [1, 7, 7], [0, 7, 7]]
[[0, 0, 1], [1, 0, 1], [0, 0, 1], [1, 0, 1], [0, 0, 1], [1, 0, 1], [0, 0, 1], [1, 0, 1], [0, 0, 1], [1, 0, 1], [0, 0, 1], [1, 0, 1], [0, 0, 1], [1, 0, 1], [0, 0, 1], [1, 0, 1]]
[[1, 0, 2], [0, 0, 3], [1, 0, 4], [0, 0, 5], [1, 0, 6], [0, 0, 4], [1, 0, 3], [0, 0, 2], [1, 0, 2], [0, 0, 3], [1, 0, 4], [0, 0, 5], [1, 0, 6], [0, 0, 4], [1, 0, 3], [0, 0, 2]]

a=State(0)不创建类的新实例吗?如果是这样，为什么结果是这样呢?

_state不是类的数据成员，对于类的每个实例都是不同的吗?

我做错了什么!

Answer 1

阅读一些文档，并找出它。

在类定义下定义任何变量都将使其成为"静态数据成员"，一个类变量而不是实例变量。必须在构造函数中定义所有实例变量!

class Stae:
def __init__( self, value ):
        'constructor call with value 0 to load intial pos, and with 1 to load blank board'
        self._state = []