Fix IndexError: Accessing an index outside the bounds of a sequence

Tue, 14 Jul 2026 09:25:00 +0800

An IndexError in Python is a common exception that indicates an attempt to access an element in a sequence (like a list, tuple, or string) using an index that is outside the valid range of indices for that sequence. This error is a clear signal that your code is trying to reference a position that simply does not exist within the given data structure. Resolving an IndexError typically involves carefully reviewing how indices are calculated and used, ensuring they always fall within the permissible bounds of the sequence’s length.

Fix IndexError: Python list index out of range error

Tue, 09 Jun 2026 12:44:04 +0800

1. Symptoms

When a Python IndexError occurs, your program terminates immediately with an error traceback. The error message indicates which type of sequence caused the problem and the invalid index that was accessed.

# Example error output
Traceback (most recent call last):
  File "example.py", line 5, in <module>
    value = my_list[10]
IndexError: list index out of range
---

Common error message variations include:

```python
# List index out of range
numbers = [1, 2, 3]
print(numbers[5])

# Tuple index out of range
coordinates = (10, 20, 30)
print(coordinates[-100])

# String index out of range
text = "Hello"
print(text[10])

# Negative index out of range
items = []
print(items[-1])

The symptoms you might observe include:

List on ErrorVault — Developer Error Code Dictionary

Fix IndexError: Accessing an index outside the bounds of a sequence

Fix IndexError: Python list index out of range error

1. Symptoms