如何在NumPy中为矩阵添加保护环？

跟进你的评论:

>>> import numpy
>>> a = numpy.array(range(9)).reshape((3,3))
>>> b = numpy.zeros(tuple(s+2 for s in a.shape), a.dtype)
>>> b[tuple(slice(1,-1) for s in a.shape)] = a
>>> b
array([[0, 0, 0, 0, 0],
       [0, 0, 1, 2, 0],
       [0, 3, 4, 5, 0],
       [0, 6, 7, 8, 0],
       [0, 0, 0, 0, 0]])

这是一个不太通用但易于理解的Alex的答案版本:

>>> a = numpy.array(range(9)).reshape((3,3))
>>> a
array([[0, 1, 2],
       [3, 4, 5],
       [6, 7, 8]])
>>> b = numpy.zeros(a.shape + numpy.array(2), a.dtype)
>>> b
array([[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]])
>>> b[1:-1,1:-1] = a
>>> b
array([[0, 0, 0, 0, 0],
       [0, 0, 1, 2, 0],
       [0, 3, 4, 5, 0],
       [0, 6, 7, 8, 0],
       [0, 0, 0, 0, 0]])