实现滑动 window 与三个输入变量，列表，window 大小和使用 python 向前移动大小？

Question

I have a list like this,

  l=[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]

Now I want to apply a sliding window of size five (n1), but it will move forward by three steps(n2).

The desired output I am looking for if n1=5 and n2=3 is,

[1,2,3,4,5],[4,5,6,7,8],[7,8,9,10,11],[10,11,12,13,14],[13,14,15,16,17],[16,17,18,19,20]

I could use following code,

[ thelist[x:x+size] for x in range( len(thelist) - size + 1 ) ]  # but this returns only one 
forward move.

How to move it more than 1?

I can use for loop, but execution time will be huge.

How to implement it with less execution time?

Answer 1

Try this:

[thelist[x: x + 5] for x in range(0,len(thelist),3) if x + 5 <= len(thelist)]

Output:

[[1, 2, 3, 4, 5],
 [4, 5, 6, 7, 8],
 [7, 8, 9, 10, 11],
 [10, 11, 12, 13, 14],
 [13, 14, 15, 16, 17],
 [16, 17, 18, 19, 20]]