获取一维 np 数组的片段

Question

I am very new to python and machine learning.

Let's say that I have a 1D np array (with both numbers and NaN) with one column and 1308 rows and want to create two variables:

train_outcome = outcome[0:891, 0]
y_pred =  outcome[891:, 0]

I tried this and got the obvious <IndexError: too many indices for the array: array is 1-dimensional, but 2 were indexed>.

I was so desperate that I converted it back to a DF to make the operation. There must be an easier way to achieve this.

Answer 1

If the array has 1 dimension, there is no need for a comma. Here is how I'd do it:

train_outcome = outcome[:891]
y_pred = outcome[891:]

Answer 2

Use np.split for a one-liner:

train_outcome, y_pred = np.split(outcome, [891])