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# How does it work ?

f = 1 A = [[1, 2, 3], [2, 3, 4], [3, 4, 5]] for i in range(0, 3): f =f*i for j in range(0, 3): A[i][j] = f print(A)

3 Answers

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You can index arrays by [], each position is numbered from 0 to length-1. If you store arrays in arrays, you can do it for the inner lists too. So A[0][2] is 3 (first element of outer array, and there the third element).
The embedded for loops create the indexes for the 2d array: two numbers i and j from 0 to 2.
And then A[i][j] will be changed to what f is now.
You only have to play this out in your mind or on paper step by step.
The interesting point is line 4. Let's do this for i == 0:
f = 1*0 -> f == 0, right?
So from now on, whatever i will be, f will remain 0 (0*1, 0*2).
And if f is always 0, then every spot of the array will be set to 0 in line 6.

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the answer is likely to be?

0

Have you read my post?