+ 2
squares = [0, 1, 4, 9, 16, 25, 36, 49, 64, 81] print(squares[2:6]) how does it result in [4, 9, 16, 25] I don't und2
Why does does it not start at one
3 ответов
+ 2
Indexing starts from 0 for lists , so squares[0] is 0 , squares[1] is 1 and so on , basically that 2:6 is index numbers for starting and ending point .
+ 1
first list item is at index 0
2nd is at 1
3rd is at 2
and so on... so, last is at list length-1
slicing get first argument as start index, and second as last (not included), so [2:6] should return third to sixth (included, as seventh is not included)...
0
these answers are correct. one tip about slicing: thankfully, when one slices by indexing from the endpoints (positive indices for the beginning of the slice and negative ones for the end), the slice indices correspond with how many items are going to be removed from the start or end of the sequence. for example “abcde”[2:-1] would chop off “ab” and “e” leaving “cd”