examples - python append array to array numpy

Prepend element to numpy array (2)

I have the following numpy array

import numpy as np

X = np.array([[5.], [4.], [3.], [2.], [1.]])

I want to insert [6.] at the beginning. I've tried:

X = X.insert(X, 0)

how do I insert into X?

You can try the following

X = np.append(arr = np.array([[6]]), values = X, axis= 0)

Instead of inserting 6 to the existing X, let append 6 by X.

So, first argument arr is numpy array of scalar 6, second argument is your array to be added, and third is the place where we want to add

numpy has an insert function that's accesible via np.insert with documentation.

You'll want to use it in this case like so:

X = np.insert(X, 0, 6., axis=0)

the first argument X specifies the object to be inserted into.

The second argument 0 specifies where.

The third argument 6. specifies what is to be inserted.

The fourth argument axis=0 specifies that the insertion should happen at position 0 for every column. We could've chosen rows but your X is a columns vector, so I figured we'd stay consistent.