Python for Loops: Iterate over Sequences

This guide explains for Loops: Iterate over Sequences through a focused example and practical reasoning. No prior knowledge of this specific operation is required.

Understanding the Concept

A for loop obtains items from an iterable, including a list, string, tuple, range or dictionary. It handles advancing to the next item automatically.

When You Would Use This

Print product labels from a small list.

Step-by-Step Example

product_names = ["Notebook", "Marker", "Folder"]
for product_name in product_names:
    print("Product:", product_name)

How the Example Works

The loop binds product_name to each list element in order and executes the body three times. It does not modify the list.

Example Output

Product: Notebook
Product: Marker
Product: Folder

Try It Yourself

Loop through the characters of one product name and print one character per line.

Common Beginner Mistakes

Using a manual counter for every simple iteration.
Forgetting that iterating over a dictionary visits keys by default.
Changing a list’s size while iterating over it.

Key Takeaways

A for loop obtains items from an iterable, including a list, string, tuple, range or dictionary.
The loop binds product_name to each list element in order and executes the body three times.
Avoid this mistake: Using a manual counter for every simple iteration.