如何使用广播将一个矩阵的每一行复制到另一个矩阵的每一行？

Question

如果我有以下矩阵：

a = np.array([['A'], ['B'], ['C']])
b = np.array([['0'], ['0'], ['0'], ['0'], ['0'], ['0']])

我想获得以下内容：

c = np.array([['A'], ['0'], ['B'], ['0'], ['C'], ['0']])

有没有办法使用某种类型的 numpy broadcast/vectorized 解决方案而不是 for 循环来获取 c？

Answer 1

瞧：

c = np.reshape(b, (3, 2, 1))
c[:,0]=a
c.shape=6,1
c
array([['A'],
       ['0'],
       ['B'],
       ['0'],
       ['C'],
       ['0']], 
      dtype='<U1')

Answer 2

用于在 b 中进行原位编辑 -

b[::2] = a

要在新数组中进行这些更改，请复制并编辑 -

c = b.copy()
c[::2] = a

如何使用广播将一个矩阵的每一行复制到另一个矩阵的每一行？

How to copy every row of one matrix into every other row of another matrix using broadcasting?

numpy

python-2.7

array-broadcasting