Creating NumPy ndarrays

An ndarray is an extremely high-performant and space-efficient data structure for multidimensional arrays.

First, we need to import the NumPy library, as follows:

import numpy as np

Next, we will start creating a 1D ndarray.

Creating 1D ndarrays

The following line of code creates a 1D ndarray:

arr1D = np.array([1.1, 2.2, 3.3, 4.4, 5.5]); 
arr1D

This will give the following output:

array([1.1, 2.2, 3.3, 4.4, 5.5])

Let's inspect the type of the array with the following code:

type(arr1D)

This shows that the array is a NumPy ndarray, as can be seen here:

numpy.ndarray

We can easily create ndarrays of two dimensions or more.

Creating 2D ndarrays

To create a 2D ndarray, use the following code:

arr2D = np.array([[1, 2], [3, 4]]); 
arr2D

The result has two rows and each row has two values, so it is a 2 x 2 ndarray, as illustrated in the following code snippet:

array([[1, 2],
      ...