What is :: (double colon) in numpy like in myarray[0::3]?
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What is :: (double colon) in Python?
I read the question What is :: (double colon) in Python when subscripting sequences?, but this not answer what myarray[x::y] mean.
Answer
It prints every yth element from the list / array
>>> a = [1,2,3,4,5,6,7,8,9]
>>> a[::3]
[1, 4, 7]
The additional syntax of a[x::y] means get every yth element starting at position x
ie.
>>> a[2::3]
[3, 6, 9]