<human>:  numpy with python: convert 3d array to 2d
<bot>: Here is some code to convert a 3d array `img` of dimensions 4x2x3 to a 2d array  of dimensions 3x8

img.transpose(2, 0, 1).reshape(3, -1)

#Warning: this code generation is experimental. Please inspect the code for any bugs before executing.