What is the time complexity of accessing an element in an array by index in Python?

Understanding Time Complexity of Array Access

1. Definition of Time Complexity: Time complexity is a computational concept that describes the amount of time it takes to run an algorithm as a function of the length of the input. It helps in analyzing the efficiency of an algorithm or operation.

2. Accessing Elements in an Array: In Python, an array can be represented using a list. Accessing an element by its index in a list involves directly retrieving the value at that specific position.

3. Constant Time Access: The operation to access an element by index is performed in constant time, denoted as $O(1)$. This is because the computer calculates the memory address of the desired element using the base address and the index without having to iterate through the list.

Summary

• Accessing an element by its index in a Python list (array) is a constant-time operation, which is expressed in time complexity as $O(1)$. This means that the time taken to access an element does not depend on the size of the array. It remains consistent regardless of how many elements are present.