image=[[1,1,1],[1,1,0],[1,0,1]]
visited = [[False] * len(image[0])] * len(image)
visited[0][0] = True
print((visited[1][0]))
Shouldn't the above python code print False? Why is the entire column being assigned as True?
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Indrajith Shetty
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You should probably be using numpy if you want 2D arrays. – o11c Jun 16 '18 at 00:39
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The reference to [False] * len(image [0]) is repeated len(image) times, so modifying the first element of visited affects the second (and third).
deepyaman
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That is it. I used to think it would create new `[False] * len(image [0])`. It just creates new reference. – Indrajith Shetty Jun 16 '18 at 00:36