On Tue, Nov 11, 2008 at 7:32 PM, <[EMAIL PROTECTED]> wrote: > I want to construct a 2-dimensional array from a List but I cannot > find a simple way of changing any element. For example, construct a > 3x3 array like this:- > >>> x=[0,0,0] > x=[x]*3 > this produces [[0,0,0],[0,0,0],[0,0,0]. So far so good. > How do I change the value of any element to produce (say) > [[99,0,0],[0,0,0],[0,0,0]] ? >
First of all, this is not a "2-d array". It is a list of lists. Each element in x is a list consisting of three elements. so x[0] is a list (x[0])[0] is the first element of that list. So what you want is >>>x[0][0] = 99 ***In this case, each list inside of x refers to the same object. Any changes you make to one row will appear in all of them. >>> a = x[0] >>> a [0, 0, 0] >>> a[0] = 99 >>> a [99, 0, 0] >>> x [[99, 0, 0], [99, 0, 0], [99, 0, 0]] > gordc > -- > http://mail.python.org/mailman/listinfo/python-list >
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