List Index Out of Range: A list index error occurs in Python when we try to access an undefined element from the list. Therefore the only way to avoid this error is to specify the index of the list elements properly. In the above example, we have created a list named “list_fruits” with three values apple, banana and orange. So if you access invalid indices in your Python list, the error “List index out of range” is generated. indexerror list index out of range
For example, if you try to access a list element with index 100, but your lists only contain three elements, Python will throw an index error telling you that the list index is out of range. Then index out of range means that the code is trying to access a matrix or vector outside of its bounds. For example, x = rndn(5, 1); y = x[6, 1]; would cause this error, because it is trying to access the 6th element out of a total of 5.
In Hindi:
सूची सूचकांक सीमा से बाहर: जब हम सूची से एक अपरिभाषित तत्व तक पहुँचने का प्रयास करते हैं तो पायथन में एक सूची सूचकांक त्रुटि होती है। इस त्रुटि से बचने का एकमात्र तरीका सूची तत्वों की अनुक्रमणिका को ठीक से निर्दिष्ट करना है। उपरोक्त उदाहरण में, हमने सेब, केला और संतरे के तीन मूल्यों के साथ “list_fruits” नाम की एक सूची बनाई है। यदि आप अपनी पायथन सूची में अमान्य सूचकांकों तक पहुँचते हैं, तो त्रुटि “सूची सूचकांक सीमा से बाहर” उत्पन्न होती है।
उदाहरण के लिए, यदि आप इंडेक्स 100 के साथ एक सूची तत्व तक पहुंचने का प्रयास करते हैं, लेकिन आपकी सूचियों में केवल तीन तत्व होते हैं, तो पायथन आपको यह बताते हुए एक इंडेक्स त्रुटि फेंक देगा कि सूची इंडेक्स सीमा से बाहर है। सीमा से बाहर अनुक्रमणिका का अर्थ है कि कोड किसी मैट्रिक्स या वेक्टर को उसकी सीमा से बाहर एक्सेस करने का प्रयास कर रहा है। उदाहरण के लिए, x = rndn(5, 1); वाई = एक्स [6, 1]; इस त्रुटि का कारण होगा, क्योंकि यह कुल 5 में से 6 वें तत्व तक पहुंचने का प्रयास कर रहा है। list assignment index out of range
How to Create a List in Python
To create a list object in Python, you need to:
- Give the list a name,
- Then use the assignment operator, =,
- and include 0 or more list items inside square brackets,[]. Each list item needs to be separated by a comma.
Also, Read- Application of Linked List, Benefits & Types of Linked List, Conclusions, FAQs… Read More
For example, to create a list of names you would do the following:
- names = [“Kelly”, “Nelly”, “Jimmy”, “Lenny”]
- The code above created a list called names that has four values: Kelly, Nelly, Jimmy, and Lenny.
How to Check the Length of a List in Python
So to check the length of a list in Python, use Python’s built-in len() method.
- len() will return an integer, which will be the number of items stored in the list.
- For e.g. names = [“Kelly”, “Nelly”, “Jimmy”, “Lenny”]
- #create a variable called name_length to store the length of the list
- name_length = len(names)
- #print value of the variable to the console
- print(name_length)
- #output
- #4
There are four items stored in the list, therefore the length of the list will be four.
How to Access Individual List Items in Python
Each item in a list has its own index number.
- Indexing in Python, and most modern programming languages, start at 0.
- This means that the first item in a list has an index of 0, the second item has an index of 1, and so on.
- You can use the index number to access the individual item.
- To access an item in a list using its index number, first, write the name of the list. Then, inside square brackets, including the integer that corresponds with the item’s index number.
- Taking the example from earlier, this is how you would access each item inside the list using its index number:
names = [“Kelly”, “Nelly”, “Jimmy”, “Lenny”]
- names[0] # Kelly
- names[1] # Nelly
- names[2] # Jimmy
- names[3] # Lenny
You can also use negative indexing to access items inside lists in Python. To access the last item, you use the index value of -1. To access the second to last item, you use the index value of -2.
Here is how you would access each item inside a list using negative indexing:
For e.g. names = [“Kelly”, “Nelly”, “Jimmy”, “Lenny”]
- names[-4] # Kelly
- names[-3]# Nelly
- names[-2] # Jimmy
- names[-1] # Lenny
Also, Read- Youtube List of Subscribers, List of Most Subscribed Channels, Numbers of Youtube Channels, FAQs… Read More
Why does the Indexerror: list index out of range error occurs in Python?
Using an index number that is out of the range of the list
You’ll get the Indexerror: list index out of range error when you try and access an item using a value that is out of the index range of the list and does not exist.
This is quite common when you try to access the last item of a list, or the first one if you’re using negative indexing.
Let’s go back to the list we’ve used so far.
names = [“Kelly”, “Nelly”, “Jimmy”, “Lenny”]
Say I want to access the last item, “Lenny”, and try to do so by using the following code:
print(names[4])
- #output
- #Traceback (most recent call last):
- #File “/Users/dionysialemonaki/python_articles/demo.py”, line 3, in
- #print(names[4])
- #IndexError: list index out of range
- Generally, the index range of a list is 0 to n-1, with n being the total number of values in the list.
- With the total values of the list above being 4, the index range is 0 to 3.
- Now, let’s try to access an item using negative indexing.
- Then say I want to access the first item in the list, “Kelly”, by using negative indexing.
- For e. g. names = [“Kelly”, “Nelly”, “Jimmy”, “Lenny”]
- print(names[-5])
- #output
- #Traceback (most recent call last):
- #File “/Users/dionysialemonaki/python_articles/demo.py”, line 3, in
- #print(names[-5])
- #IndexError: list index out of range
When using negative indexing, the index range of a list is -1 to -n, where -n is the total number of items contained in the list. indexerror list assignment index out of range
Then with the total number of items in the list being 4, the index range is -1 to -4.
Using the wrong value in the range() function in a Python for loop
You’ll get the Indexerror: list index out of range error when iterating through a list and trying to access an item that doesn’t exist.
- One common instance where this can occur is when you use the wrong integer in Python’s range() function.
- So the range() function typically takes in one integer number, which indicates where the counting will stop.
- For example, range(5) indicates that the counting will start from 0 and end at 4.
- So, by default, the counting starts at position 0, is incremented by 1 each time, and the number is up to – but not including – the position where the counting will stop.
Useful Links:
Best Shampoo Brands in India, www.lightinthebox.com, List of Eclipse in 2021 in India, E-Pass Jharkhand Online Registration, Expect Meaning in Hindi.
Let’s take the following example:
names = [“Kelly”, “Nelly”, “Jimmy”, “Lenny”]
for name in range(5):
print(names[name])
- #output
- #Kelly
- #Nelly
- #Jimmy
- #Lenny
- #Traceback (most recent call last):
- #File “/Users/dionysialemonaki/python_articles/demo.py”, line 7, in
- #print(names[name])
- #IndexError: list index out of range
Here, the list of names has four values.
I wanted to loop through the list and print out each value.
When I used range(5) I was telling the Python interpreter to print the values that are at the positions 0 to 4.
However, there is no item in position 4.
You can see this by first printing out the number of the position and then the value at that position.
- #0
- #Kelly
- #1
- #Nelly
- #2
- #Jimmy
- #3
- #Lenny
- #4
- #Traceback (most recent call last):
- #File “/Users/dionysialemonaki/python_articles/demo.py”, line 8, in
- #print(names[name])
- #IndexError: list index out of range
Then you see that at position 0 is “Kelly”, at position 1 is “Nelly”, at position 2 is “Jimmy” and at position 3 is “Lenny”.
When it comes to position four, which was specified with range(5) which indicates positions of 0 to 4, there is nothing to print out and therefore the interpreter throws an error.
One way to fix this is to lower the integer in range():
names = [“Kelly”, “Nelly”, “Jimmy”, “Lenny”]
for name in range(4):
print(name)
print(names[name])
- #output
- #0
- #Kelly
- #1
- #Nelly
- #2
- #Jimmy
- #3
- #Lenny
Another way to fix this when using a for loop is to pass the length of the list as an argument to the range() function.
You do this by using the len() built-in Python function, as shown in an earlier section:
For e.g. names = [“Kelly”, “Nelly”, “Jimmy”, “Lenny”]
for name in range(len(names)):
print(names[name])
- #output
- #Kelly
- #Nelly
- #Jimmy
- #Lenny
Useful Links:
Tyre Brands in India, Bazar-Virtual.ca, List of Scans During Pregnancy, E-Uparjan Jharkhand, Gratitude Meaning in Hindi.
When passing len() as an argument to range(), make sure that you don’t make the following mistake:
names = [“Kelly”, “Nelly”, “Jimmy”, “Lenny”]
for name in range(len(names) + 1):
print(names[name])
After running the code, you’ll again get an IndexError: list index out of range error:
- #Kelly
- #Nelly
- #Jimmy
- #Lenny
- #Traceback (most recent call last):
- #File “/Users/dionysialemonaki/python_articles/demo.py”, line 4, in
- #print(names[name])
- #IndexError: list index out of range
FAQs
How do I stop the list assignment index out of range?
The “index error: list assignment index out of range” is raised when you try to assign an item to an index position that does not exist. So to solve this error, you can use append() to add an item to a list. You can also initialize a list before you start inserting values to avoid this error.
How do you initialize a list in Python?
To initialize a list in Python assign one with square brackets, initialize with the list() function, create an empty list with multiplication, or use a list comprehension. Hence this is the most common way to declare a list in Python is to use square brackets.
Also, Read- UGC Care List of Journals 2021-2022, Work & Importance of UGC Care, Backstory of UGC… Read More
Why does Python say the list index is out of range?
The error “list index out of range” arises if you access invalid indices in your Python list. For example, if you try to access the list element with index 100 but your lists consist only of three elements, Python will throw an IndexError telling you that the list index is out of range
How do you fix a string index out of range in Python?
The “TypeError: string index out of range” error is raised when you try to access an item at an index position that does not exist. Therefore you solve this error by making sure that your code treats strings as if they are indexed from position 0. list index out of range python
