http://www.velocityreviews.com/forums/(E-Mail Removed) wrote:

> On Nov 11, 7:48 pm, (E-Mail Removed) wrote:

>> gc_ott:

>>

>>> How do I change the value of any element to produce (say)

>>> [[99,0,0],[0,0,0],[0,0,0]] ?

>>> gordc

>> To create a 2D list, that is a list of lists:

>> x = [[0] * ncols for i in nrows]

>> (Don't do what you were doing, because you end with many references to

>> the same list, and that will give you troubles.)

>>

>> To set an item you do just:

>> x[0][0] = 99

>>

>> Bye,

>> bearophile

>

> Many thanks, I don't think I would ever 'discovered' this.
If you are trying to emulate numerical arrays, you may want to use numpy, instead.

http://numpy.scipy.org/
import numpy

x = numpy.zeros([3,3], dtype=int)

x[0,0] = 99

--

Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma

that is made terrible by our own mad attempt to interpret it as though it had

an underlying truth."

-- Umberto Eco