python - Replace subarrays in numpy -

given array,

>>> n = 2 >>> = numpy.array([[[1,1,1],[1,2,3],[1,3,4]]]*n) >>> array([[[1, 1, 1],         [1, 2, 3],         [1, 3, 4]],         [[1, 1, 1],         [1, 2, 3],         [1, 3, 4]]]) 

i know it's possible replace values in succinctly so,

>>> a[a==2] = 0 >>> array([[[1, 1, 1],         [1, 0, 3],         [1, 3, 4]],         [[1, 1, 1],         [1, 0, 3],         [1, 3, 4]]]) 

is possible same entire row (last axis) in array? know a[a==[1,2,3]] = 11 work , replace elements of matching subarrays 11, i'd substitute different subarray. intuition tells me write following, error results,

>>> a[a==[1,2,3]] = [11,22,33] traceback (most recent call last):   file "<stdin>", line 1, in <module> valueerror: array not broadcastable correct shape 

in summary, i'd is:

array([[[1, 1, 1],         [11, 22, 33],         [1, 3, 4]],         [[1, 1, 1],         [11, 22, 33],         [1, 3, 4]]]) 

... , n of course is, in general, lot larger 2, , other axes larger 3, don't want loop on them if don't need to.

---

update: [1,2,3] (or whatever else i'm looking for) not @ index 1. example:

a = numpy.array([[[1,1,1],[1,2,3],[1,3,4]], [[1,2,3],[1,1,1],[1,3,4]]]) 

you have little more complicated acheive want.

you can't select slices of arrays such, can select specific indexes want.

so first need construct array represents rows wish select. ie.

data = numpy.array([[1,2,3],[55,56,57],[1,2,3]])  to_select = numpy.array([1,2,3]*3).reshape(3,3) # 3 rows of [1,2,3]  selected_indices = data == to_select # array([[ true,  true,  true], #        [false, false, false], #        [ true,  true,  true]], dtype=bool)  data = numpy.where(selected_indices, [4,5,6], data) # array([[4, 5, 6], #        [55, 56, 57], #        [4, 5, 6]])  # done in 1 step, perhaps not clear intent data = numpy.where(data == numpy.array([1,2,3]*3).reshape(3,3), [4,5,6], data) 

numpy.where works selecting second argument if true , third argument if false.

you can use select 3 different types of data. first array has same shape selected_indices, second value on own (like 2 or 7). first complicated can of shape can broadcast same shape selected_indices. in case provided [1,2,3] can stacked array shape 3x3.