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[Solved] Python Loop: List Index Out of Range

Hello Guys, How are you all? Hope You all Are Fine. Today I get the following error Python Loop: List Index Out of Range in python. So Here I am Explain to you all the possible solutions here.

Without wasting your time, Let’s start This Article to Solve This Error.

How Python Loop: List Index Out of Range Error Occurs?

Today I get the following error Python Loop: List Index Out of Range in python.

How To Solve Python Loop: List Index Out of Range Error ?

  1. How To Solve Python Loop: List Index Out of Range Error ?

    To Solve Python Loop: List Index Out of Range Error

  2. In your for loop, you're iterating through the elements of a list a. But in the body of the loop, you're using those items to index that list, when you actually want indexes.
  3. Python Loop: List Index Out of Range

    To Solve Python Loop: List Index Out of Range Error

  4. In your for loop, you're iterating through the elements of a list a. But in the body of the loop, you're using those items to index that list, when you actually want indexes.

Solution 1

  1. In your for loop, you’re iterating through the elements of a list a. But in the body of the loop, you’re using those items to index that list, when you actually want indexes.
    Imagine if the list a would contain 5 items, a number 100 would be among them and the for loop would reach it. You will essentially attempt to retrieve the 100th element of the list a, which obviously is not there. This will give you an IndexError.

We can fix this issue by iterating over a range of indexes instead:

for i in range(len(a))

and access the a‘s items like that: a[i]. This won’t give any errors.

  1. In the loop’s body, you’re indexing not only a[i], but also a[i+1]. This is also a place for a potential error. If your list contains 5 items and you’re iterating over it like I’ve shown in the point 1, you’ll get an IndexError. Why? Because range(5) is essentially 0 1 2 3 4, so when the loop reaches 4, you will attempt to get the a[5] item. Since indexing in Python starts with 0 and your list contains 5 items, the last item would have an index 4, so getting the a[5] would mean getting the sixth element which does not exist.

To fix that, you should subtract 1 from len(a) in order to get a range sequence 0 1 2 3. Since you’re using an index i+1, you’ll still get the last element, but this way you will avoid the error.

  1. There are many different ways to accomplish what you’re trying to do here. Some of them are quite elegant and more “pythonic”, like list comprehensions:

b = [a[i] + a[i+1] for i in range(len(a) - 1)]

This does the job in only one line.

Solution 2

When you call for i in a:, you are getting the actual elements, not the indexes. When we reach the last element, that is 3b.append(a[i+1]-a[i]) looks for a[4], doesn’t find one and then fails. Instead, try iterating over the indexes while stopping just short of the last one, like

for i in range(0, len(a)-1): Do something

Your current code won’t work yet for the do something part though 😉

Summery

It’s all About this issue. Hope all solution helped you a lot. Comment below Your thoughts and your queries. Also, Comment below which solution worked for you? Thank You.

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