Suppose I have a numpy array like this:
arr = np.array([[1,1,1,1], [2,2,2,2], [3,3,3,3], [4,4,4,4])
I also have a list that determines the intended lengths:
lens = [1,2,3,4]
Is there an elegant and Pythonic way to return a new array, with each corresponding element selected using the lens variable?
The output should be:
[[1], [2,2],[3,3,3], [4,4,4,4]]
If each Numpy arr list element size is less than 5 this works.
Use zip:
[a[:i].tolist() for a, i in zip(arr, lens)]
Output:
[[1], [2, 2], [3, 3, 3], [4, 4, 4, 4]]
This could be a possible solution:
res = []
for a,i in zip(arr, lens):
res.append(a[:i].tolist())
print(res)
Assuming arr is equal in length as lens:
[arr[i][:v].tolist() for i,v in enumerate(lens)]
Output: [[1], [2, 2], [3, 3, 3], [4, 4, 4, 4]]