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The matrix is m = [[1, 2], [3, 4], [5, 6]], three rows of two.
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
The matrix is m = [[1, 2], [3, 4], [5, 6]], three rows of two. Write comprehensions for (1) the list of the sums of each row, (2) the flat list of all the numbers, and (3) the transposed matrix, two rows of three.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Plan.
- The sum of each row:
[sum(row) for row in m]. - Flatten, with the loops in the nested order:
[x for row in m for x in row]. - Transpose: for each position
iof a row, collect thei-th item of every row:[[row[i] for row in m] for i in range(2)].
Check. The row sums are 3, 7 and 11. The flat list is 1 to 6. The transpose takes the first items (1, 3, 5) as the first row, and the second items (2, 4, 6) as the second row.
Answer: [3, 7, 11], [1, 2, 3, 4, 5, 6] and [[1, 3, 5], [2, 4, 6]].
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