Argument order rules in Python - Mini Project: Build & Apply

Argument order rules

📖 Scenario: Imagine you are creating a simple program to greet people with their name and age. You want to learn how to write functions with different types of arguments in the right order.

🎯 Goal: You will build a function that takes arguments in the correct order: positional, default, and keyword-only arguments. Then you will call this function correctly to print a greeting message.

📋 What You'll Learn

Create a function with one positional argument called name

Add one default argument called age with default value 30

Add one keyword-only argument called city without a default

Call the function with correct argument order and print the greeting

💡 Why This Matters

🌍 Real World

Functions with clear argument order are used in real programs to avoid confusion and bugs when many options are needed.

💼 Career

Understanding argument order is important for writing clean, maintainable code in any software development job.

1

Create the greeting function with positional and default arguments

Define a function called greet that takes one positional argument name and one default argument age set to 30. Inside the function, write a print statement that says: "Hello {name}, you are {age} years old."

Python

# Define the greet function with name and age
# Your code here

Need a hint?

Remember, positional arguments come first, then default arguments with an equals sign.

2

Add a keyword-only argument called city

Modify the greet function to add a keyword-only argument called city after a * symbol. Inside the function, update the print statement to say: "Hello {name} from {city}, you are {age} years old."

Python

def greet(name, age=30, *):
    # Update the print statement
    # Your code here

Need a hint?

Use * to mark the start of keyword-only arguments.

3

Call the greet function with correct argument order

Write a call to the greet function with name as "Alice", age as 25, and city as "Paris". Use positional arguments for name and age, and keyword argument for city.

Python

def greet(name, age=30, *, city):
    print(f"Hello {name} from {city}, you are {age} years old.")

# Call greet with name 'Alice', age 25, city 'Paris'
# Your code here

Need a hint?

Remember to pass city as a keyword argument after the *.

4

Print the greeting message

Run the program and print the greeting message from the greet function call.

Python

def greet(name, age=30, *, city):
    print(f"Hello {name} from {city}, you are {age} years old.")

greet("Alice", 25, city="Paris")

# The greeting is printed by the function call above

Need a hint?

The function call already prints the greeting. Just run the program.