Creating a matrix?

[Peter Maas]

Peter Hansen wrote:
>  >>> matrix[1][2] = '1'
>  >>> matrix
> [['0', '0', '1', '0'], ['0', '0', '1', '0'], ['0', '0', '1', '0'], ['0', 
> '0', '1
> ', '0']]
> 
> Notice that each of the inner lists contains four seperate references
> to the string '0', but the outer repetition simply copies the inner
> list four times, resulting in four references to the same inner list!
> Changing any one element affects the same entry in each of the other
> three lists...

Sorry:

matrix = [['0']*N for i in range(N)]

Mit freundlichen Gruessen,

Peter Maas

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