numpy fromstring 不推荐使用 frombuffer 代替

Question

在 Python 代码中使用 numpy 1.18.1

` def printBoard(self): current = self.player other = self.player % 2 + 1

    currBin   = '{:049b}'.format(self.current_position)
    currRev = currBin[::-1]

    cArr = (np.fromstring(currRev,'u1') - ord('0'))*current

    other_position = self.current_position^self.mask
    othBin   = '{:049b}'.format(other_position)
    othRev = othBin[::-1]

    oArr = (np.fromstring(othRev,'u1') - ord('0'))*other

    tArr =  oArr+cArr

    brd = np.reshape(tArr,(7,7),order = 'F')
    for y in range(bitBoard.HEIGHT,-1,-1):
        for x in range(bitBoard.WIDTH):
            print(brd[y,x],end = ' ')
        print()
    print()
    `

线：

cArr = (np.fromstring(currRev,'u1') - ord('0'))*current

给出以下警告：

DeprecationWarning: The binary mode of fromstring is deprecated, as it behaves surprisingly on    unicode inputs. Use frombuffer instead
  cArr = (np.fromstring(currRev,'u1') - ord('0'))*current

用 'frombuffer' 替换 'fromstring' 会出现以下错误：

cArr = (np.frombuffer(currRev,'u1') - ord('0'))*current

TypeError: a bytes-like object is required, not 'str'

尽管进行了一些谷歌搜索，但我找不到我应该使用的东西。有人可以帮忙吗？

谢谢你。

艾伦

Answer 1

代码的相关部分是产生currRev. 从中我可以构建这个例子：

In [751]: astr = '{:049b}'.format(123)[::-1]                                                   
In [752]: astr                                                                                 
Out[752]: '1101111000000000000000000000000000000000000000000'

你的警告：

In [753]: np.fromstring(astr, 'u1')                                                            
/usr/local/bin/ipython3:1: DeprecationWarning: The binary mode of fromstring is deprecated, as it behaves surprisingly on unicode inputs. Use frombuffer instead
  #!/usr/bin/python3
Out[753]: 
array([49, 49, 48, 49, 49, 49, 49, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48,
       48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48,
       48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48],
      dtype=uint8)

frombuffer 想要一个字节串，所以让我们创建一个：

In [754]: astr.encode()                                                                        
Out[754]: b'1101111000000000000000000000000000000000000000000'
In [755]: np.frombuffer(astr.encode(),'u1')                                                    
Out[755]: 
array([49, 49, 48, 49, 49, 49, 49, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48,
       48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48,
       48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48],
      dtype=uint8)

其余的行：

In [756]: _-ord('0')                                                                           
Out[756]: 
array([1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0], dtype=uint8)

获取相同数组的另一种方法：

In [758]: np.array(list(astr),'uint8')                                                         
Out[758]: 
array([1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0], dtype=uint8)