Get Random Index from List in Python (4 Examples)
In this post, you’ll learn how to get a random index from a list in the Python language.
Here is an overview of the tutorial:
Let’s dive into it!
Load Library & Create Sample List
The first step in this tutorial will be to import the random module.
Then, we will create a sample list as follows.
my_list = [1, 'two', 3.5, 4, 5] print(my_list) # [1, 'two', 3.5, 4, 5]
As you can see,
my_list is a mixed-type list that contains three integers (e.g., 1), one string (‘two’), and one float (3.5). Now, we are ready to retrieve a random index from this list using several examples.
Example 1: Get Random Index Using random.choice() Function
The following Python syntax shows how to use the random.choice() function to randomly select an index from
random_index = random.choice(range(len(my_list))) print(random_index) # 3
Here, the random.choice() function chose a random number from 0 (the lowest valid index) to
len(my_list) - 1 (the highest valid index) by using the range() and the len() functions. The selected random number, which in our case is 3, was then assigned to the
random_index variable and finally printed into the console.
Example 2: Get Random Index Using random.randint() Function
This example is very similar to Example 1. It uses the randint() function of the random module to retrieve a random index in
my_list. Take a look.
random_index = random.randint(0, len(my_list) - 1) print(random_index) # 4
Here, the randint() function generated a random integer between 0 and
len(my_list) - 1. The randomly generated index was then assigned to
random_index and printed to the console, which in this case is 4.
Example 3: Get Random Index Using random.random() Function
Another function of the random module that can be helpful to select a random index from
my_list is the random() function. It works as follows.
random_index = int(random.random() * len(my_list)) print(random_index) # 3
In the previous Python output, the random() function generated a floating-point number between 0 and 1. Multiplied by the length of
my_list, it results in a random float value between 0 and
len(my_list). This float value is converted to an integer by using the int() function and finally printed to the console.
Example 4: Get Random Index Using NumPy
In this last example, we will use the NumPy library to select a random index from
my_list. To do so, we will first load the library.
import numpy as np
Now, we can use the random.randint() function to obtain a random index from our list as follows.
random_index = np.random.randint(0, len(my_list)) print(random_index) # 0
The code from above shows how
np.random.randint(0, len(my_list)) generates a random integer between 0 and
len(my_list), which ensures that the generated index is within the valid bounds of the list’s indices.
Video, Further Resources & Summary
Do you need more explanations on how to retrieve a random index from a list in Python? Then you should have a look at the following YouTube video of the Statistics Globe YouTube channel.
The YouTube video will be added soon.
Besides that, you could have a look at some of the related tutorials on Statistics Globe:
- Get Last Index of List in Python
- Get First Index of List in Python
- Get Next Element in List in Python
- Get Index of Multiple List Elements in Python
This post has shown how to get a random index from a list in Python. Please let me know in the comments section below if you have additional questions.
This page was created in collaboration with Paula Villasante Soriano. Please have a look at Paula’s author page to get more information about her academic background and the other articles she has written for Statistics Globe.
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