now you can still use column access
previously...
mat[2] = 1, 2, 3
needed to be converted into...
mat[0][2] = 1
mat[1][2] = 2
mat[2][2] = 3
but with column access you can do...
mat.col[2] = 1, 2, 3
Having 'row' attribute is a bit redundant since direct indexing on a matrix uses row but included for completeness.
this is a part of patch 29534, being applied separately
from patch [#29534] Change Matrix Representation and Access in Python to Conform with Standard Notation
by Andrew Hale (trumanblending)
also add an assert so invalid index access will raise an error in debug mode, without this it was quite easy to access invalid memory without meaning to.
no functional change.