Python *args and **kwargs

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Python *args and **kwargs

Leverage variadic parameters to build extensible functions and wrappers.

Read examplesFollow best practices

Examples

def log_event(event_type, *details, **meta):
    print(event_type, details, meta)

log_event("login", "user123", ip="1.1.1.1")

• *details becomes a tuple of extra positional arguments.
• **meta becomes a dict of keyword arguments.

Forwarding arguments

def with_retry(func):
    def wrapper(*args, **kwargs):
        for _ in range(3):
            try:
                return func(*args, **kwargs)
            except Exception:
                continue
    return wrapper

Best practices

• Keep required parameters explicit. Move *args/**kwargs to the end.
• Document accepted arguments in docstrings even if they're flexible.
• Avoid swallowing unexpected keywords silently; validate them when possible.

Next up in your learning path

Default arguments

Combine defaults with variadic parameters.

Companion

Decorators

Use *args/**kwargs to wrap arbitrary callables.

Advanced

Type hints

Annotate variadic parameters with typing.

Reference