🏷️ Python Keyword Arguments – Write Clear and Flexible Functions

🧲 Introduction – Why Keyword Arguments Matter

When calling functions in Python, we often use positional arguments. But in many real-world scenarios—like APIs, configuration options, or user input—order shouldn’t matter.

That’s where keyword arguments shine.

They allow you to call a function by explicitly naming parameters, improving readability and making arguments order-independent.

🎯 In this guide, you’ll learn:

• What keyword arguments are and how to use them
• Differences from positional arguments
• How to mix positional and keyword arguments
• Real-world examples and best practices

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🔧 Syntax of Keyword Arguments

def function_name(param1, param2):
    # code

function_name(param1=value1, param2=value2)

💡 Key Rule: Parameter names must match those in the function definition.

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✅ Example 1: Simple Keyword Arguments

def introduce(name, age):
    print(f"My name is {name} and I am {age} years old.")

introduce(age=25, name="Alice")

🧠 Output:

My name is Alice and I am 25 years old.

📘 Explanation:
Using keywords lets you pass arguments in any order.

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🔄 Positional vs Keyword Arguments

Feature	Positional Arguments	Keyword Arguments
Order matters	✅ Yes	❌ No
Readability	Medium	✅ High
Flexibility	❌ Less flexible	✅ Highly flexible
Common in	Short functions	Config-heavy or multi-parameter funcs

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📦 Mixing Positional and Keyword Arguments

✅ Example 2:

def book_flight(from_city, to_city, airline="Delta"):
    print(f"Flight from {from_city} to {to_city} via {airline}")

book_flight("Paris", to_city="New York")

📘 Rule:
Positional arguments must come before keyword arguments.

✅ This is valid:

func(10, b=5)

❌ This is invalid:

func(a=10, 5)  # SyntaxError

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🧳 Real-World Example: Sending Email

def send_email(to, subject, body="(No Content)", cc=None):
    print(f"To: {to}")
    print(f"Subject: {subject}")
    print(f"Body: {body}")
    print(f"CC: {cc or 'None'}")

send_email(subject="Update", to="user@example.com", cc="boss@example.com")

💡 Use Case: Keyword arguments are perfect when calling functions with many optional parameters.

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⚠️ Common Mistakes

Mistake	Fix
Mixing keyword and positional wrongly	Positional args must come first
Misspelling parameter names	Match names exactly as defined in the function
Using reserved keywords as names	Avoid using Python keywords as parameter names

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📘 Summary – Key Takeaways

• ✅ Keyword arguments let you assign values by name, not position
• 🔄 You can mix positional and keyword arguments (positional first)
• 💡 Ideal for optional and named parameters
• 🧩 Keyword arguments improve readability and flexibility

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❓ FAQ Section

❓ Can keyword arguments be in any order?

Yes, as long as parameter names match, order doesn’t matter.

❓ Can I use only keyword arguments?

Yes. You can call a function with all keyword arguments:

introduce(name="Bob", age=30)

❓ What happens if I misspell a keyword?

Python will raise a TypeError:

TypeError: got an unexpected keyword argument

❓ Can keyword arguments be combined with default arguments?

Yes. They often go hand-in-hand for better flexibility.

❓ Are keyword arguments required?

No. They are optional unless specified using special syntax like *, (Python 3.8+).

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