IndexError: List Index Out of Range

Why This Happens

Python lists are zero-indexed, so a list of 3 elements has valid indices 0, 1, and 2. Accessing index 3 raises IndexError. This often occurs with off-by-one errors or empty lists.

The Problem

items = ['a', 'b', 'c']
print(items[3])

result = []
first = result[0]

The Fix

items = ['a', 'b', 'c']
if len(items) > 3:
    print(items[3])

result = []
first = result[0] if result else None

Step-by-Step Fix

1. 1

   Check list length

   Print len(your_list) to verify element count.

2. 2

   Handle empty lists

   Check if my_list: first = my_list[0].

3. 3

   Use negative indices carefully

   list[-1] gets the last element but still fails on empty lists.