On Jun 12, 7:31 pm, DarrenWeber <[EMAIL PROTECTED]> wrote: > Below is a module (matrix.py) with a class to implement some basic > matrix operations on a 2D list. Some things puzzle me about the best > way to do this (please don't refer to scipy, numpy and numeric because > this is a personal programming exercise for me in creating an > operational class in pure python for some *basic* matrix operations). > > 1. Please take a look at the __init__ function and comment on the > initialization of the list data with respect to unique memory > allocation. > > 2. In the operator overloading of __add__, __sub__, etc., the > statement isinstance(q, Matrix) raises exceptions every time. This > statement works fine outside of the class definition, but not during > the operator evaluation. What is going here? ... > > def __add__(self, q): > 'matrix addition: m3 = m1 + m2' > # if isinstance(q, Matrix): > # arg = ("q is not a matrix instance", q) > # raise TypeError, arg
Wouldn't it make more sense to raise an exception if q is NOT an instance of Matrix? -- http://mail.python.org/mailman/listinfo/python-list