Inserting slice of array objects into different slice

[ThemePark]

The problem is exactly described in error message: you can't broadcast shape 2,1 into shape 2.

But it obviously doesn't describe a solution, and a ton of research hasn't led me any nearer on a solution.

Before any advice it would be good to know what is the objective i.e. what do you want to accomplish.

The exact same result that I said I got in the first post, but without having to do it one by one. It's fine with an array of a size 2, but what if I had a size 10, 1000 or even higher? Then part of my code would look like this:

a[0]=b[0]
a[1]=b[1]
a[2]=b[2]
a[3]=b[3]
a[4]=b[4]
a[5]=b[5]
...
a[997]=b[997]
a[998]=b[998]
a[999]=b[999]

But there must be an easier way of doing this, using slicing, or list comprehension perhaps. And that's what I can't figure out how to do.