Convert a NumPy Array to a List in Python

You can use tolist() in order to convert a NumPy array to a list in Python:

my_list = my_array.tolist()

Below are the steps to convert a NumPy array to a list (as well as to a list of lists) using practical examples.

Steps to Convert a NumPy Array to a List in Python

Step 1: Create a NumPy array

To start with a simple example, create the following NumPy array:

import numpy as np

my_array = np.array([11, 22, 33, 44, 55, 66])

print(my_array)
print(type(my_array))

Run the code in Python, and you’ll get the following NumPy array:

[11 22 33 44 55 66]
<class 'numpy.ndarray'>

Note that print(type(my_array)) was added at the bottom of the code in order to demonstrate that you got a NumPy array.

Step 2: Convert the NumPy array to a List

You may use tolist() to convert the NumPy array to a list in Python:

my_list = my_array.tolist()

For our example:

import numpy as np

my_array = np.array([11, 22, 33, 44, 55, 66])

my_list = my_array.tolist()

print(my_list)
print(type(my_list))

As you can see, the NumPy array was converted to a list:

[11, 22, 33, 44, 55, 66]
<class 'list'>

Convert a NumPy Array to a List of Lists

In this section, you’ll see how to convert a two-dimensional array to a list of lists.

To begin, create the two-dimensional NumPy array:

import numpy as np

my_array = np.array([[11, 22, 33], [44, 55, 66]])

print(my_array)
print(type(my_array))
print("Number of array dimensions: " + str(my_array.ndim))

Here is the array that you’ll get:

[[11 22 33]
 [44 55 66]]
<class 'numpy.ndarray'>
Number of array dimensions: 2

You can then use tolist() to convert the array to a list of lists:

import numpy as np

my_array = np.array([[11, 22, 33], [44, 55, 66]])

my_list = my_array.tolist()

print(my_list)
print(type(my_list))

Once you run the code, you’ll get the following result:

[[11, 22, 33], [44, 55, 66]]
<class 'list'>

You can read more about tolist() by visiting the NumPy Documentation.

For an opposite scenario, check the following guide that explains how to convert a list to a NumPy array.