How to Convert 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 NumPy Array to a List in Python

Step 1: Create a NumPy array

To start with a simple example, let’s 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'>

Notice that print(type(my_array)) was added at the bottom of the code in order to demonstrate that we 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, the complete code to convert the numpy array to a list is as follows:

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 NumPy Array to a List of Lists

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

To begin, let’s 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, you may check the following guide that explains how to convert a list to a numpy array.