Python Positional Arguments vs Keyword Arguments

This guide explains positional arguments vs keyword arguments through a focused Python example. You will learn the behavior to expect, why it matters in a real program, and how to recognize the common mistakes before applying it in your own project.

What You Will Learn

Positional arguments are matched by order, whereas keyword arguments name the parameters explicitly. Keyword calls can make boolean or similarly typed parameters easier to read.

When and Why to Use It

The following example focuses on a practical use of Positional Arguments vs Keyword Arguments.

Step-by-Step Example

def create_booking(city, nights, breakfast=False):
    return f"{city}: {nights} nights; breakfast={breakfast}"

print(create_booking("Rome", 2))
print(create_booking(nights=3, city="Paris", breakfast=True))

Understanding the Example

The first call uses positional arguments and the default False. The second uses names, so the order of supplied keywords does not matter.

Expected Output

Rome: 2 nights; breakfast=False
Paris: 3 nights; breakfast=True

Important Behavior and Edge Cases

A parameter cannot receive conflicting values through both position and keyword, and positional arguments cannot follow keyword arguments in a call.

Try It Yourself

Rewrite a call with three positional arguments using explicit parameter names.

Common Beginner Mistakes

A parameter cannot receive conflicting values through both position and keyword, and positional arguments cannot follow keyword arguments in a call.
Confusing a returned value with printed output, or failing to verify a function’s behavior with different input values.
Skipping the practice step and assuming the example covers every input. Test at least one normal case and one edge case relevant to this topic.

Key Takeaways

Positional arguments are matched by order, whereas keyword arguments name the parameters explicitly.
The first call uses positional arguments and the default False.
Apply the technique deliberately, checking its documented input requirements and failure behavior before integrating it into a larger project.