What are some examples of default parameters in Python functions?

What are some examples of default parameters in Python functions?

In Python, default parameters allow you to define a function with default values for certain arguments. For example:

def greet(name='Guest'):
    return f'Hello, {name}!'

Here, if you call greet() without an argument, it will return 'Hello, Guest!'. You can also call it with a name like greet('Alice'), which will return 'Hello, Alice!'.

Can you give me another example?

Sure! Here's another example:

def add(a, b=5):
    return a + b

In this case, if you call add(3), it will return 8 (3 + 5). If you call add(3, 2), it will return 5 (3 + 2).

What happens if I don't provide a value for a parameter without a default?

If you don't provide a value for a parameter that doesn't have a default, Python will raise a TypeError. For example:

def multiply(a, b):
    return a * b

Calling multiply(3) will result in an error because b is required.

Are there any best practices for using default parameters?

Yes, some best practices include:

1. Use immutable types (like strings, numbers, or tuples) as default values to avoid unexpected behavior.
2. If you need a mutable default (like a list), use None and initialize it inside the function to prevent shared state.