Access the index of a for loop

David Y.

The Problem

How do I access the index when iterating over a sequence inside a for loop?

The Solution

We can use Python’s built-in enumerate() function to do this. For each item in an iterable sequence such as a list, this function will return a tuple containing the item’s index and the item itself. Therefore, our code will look like this:

products = ["Apples", "Oranges", "Bananas"] for idx, product in enumerate(products): print(f"{idx}: {product}")

This code will produce the following output:

0: Apples 1: Oranges 2: Bananas

If we would prefer to start the index from 1 (or any other number), we can specify this using enumerate()’s start parameter, as below:

products = ["Apples", "Oranges", "Bananas"] for idx, product in enumerate(products, start=1): print(f"{idx}: {product}")

This will produce the following output:

1: Apples 2: Oranges 3: Bananas

The index can also be accessed without using the enumerate() function by iterating over the length of the iterable sequence as below:

products = ["Apples", "Oranges", "Bananas"] for idx in range(len(products)): print(f"{idx}: {products[idx]}")

This code will produce the following output:

0: Apples 1: Oranges 2: Bananas

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