How to Convert Numpy Array to List

In this post, we will learn how to convert numpy array to list with detailed explanation and example.

Basically, there are four different ways to convert a numpy array to a Python list.

1. Using the Numpy tolist() method (simplest and easiest way).
2. Using list() function
3. Using for-loop
4. Using list comprehension

Let’s see all four ways one by one with the help of example.

To learn the Numpy library check out this article 👉 Learn Python NumPy Library with Simple Example

Using the Numpy tolist() method

Numpy provides a built-in method called tolist(), which converts a NumPy array to a Python list. Let’s see this with an example.

import numpy as np

arr = np.array([1,2,3,4,5])  # create numpy array
print(type(arr)) # check type
print(arr)

my_list = arr.tolist()  # convert numpy array to a list
print(type(my_list)) # checking type
print(my_list)

Output:

<class 'numpy.ndarray'>
[1 2 3 4 5]
<class 'list'>
[1, 2, 3, 4, 5]

Using list() function

We can also use the list() function in Python to convert a NumPy array to a list. After the tolist() method, this is one of the most common ways to convert a NumPy array to a list.

import numpy as np

arr = np.array([2,4,6,8,10])  # create numpy array
print(type(arr)) # check type
print(arr)

lst = list(arr)  # convert Numpy array to a list
print(type(lst)) # check type
print(lst)

Output:

<class 'numpy.ndarray'>
[ 2  4  6  8 10]
<class 'list'>
[2, 4, 6, 8, 10]

Using For-loop

Instead of using built-in functions or methods, you can convert a NumPy array to a list using a for loop.

import numpy as np

arr = np.array([1,2,3,5,7])  # create numpy array
print(type(arr)) # check type
print(arr)

# ---convert Numpy array to a list---

lst = [] # create a empty list

# Using for loop iterate in Numpy array (arr)
for i in arr:
    lst.append(i) # add numpy elements to a empty list

print(type(lst)) # check type
print(lst)

Output:

<class 'numpy.ndarray'>
[1 2 3 5 7]
<class 'list'>
[1, 2, 3, 5, 7]

Using list comprehension

For-loop increases the number of lines in code. So instead of using a for-loop to convert a NumPy array to a list, we can also use list comprehension. it converts a NumPy array to a list in just one line.

import numpy as np

arr = np.array([1,2,3,5,7,9,11])  # create numpy array
print(type(arr)) # check type
print(arr)

# ---convert Numpy array to a list using list comprehension---

lst = [i for i in arr] 
print(type(lst))
print(lst)

Output:

<class 'numpy.ndarray'>
[ 1  2  3  5  7  9 11]
<class 'list'>
[1, 2, 3, 5, 7, 9, 11]

In conclusion, these are four different ways to convert a NumPy array to a list. I hope this post adds some value to your life. Thank you for reading, and see you in the next article.