Overview: Python Function Parameters, Arguments and Return Values
Python functions can accept different types of inputs, from simple values to a variable number of positional or keyword arguments. Understanding how parameters and arguments work, how different parameter types can be combined, how arguments can be unpacked, and how functions return values helps in working with functions effectively.
Python Function Parameters, Arguments and Return Values: Quick Overview
| Topic | What It Covers |
|---|---|
| Parameters and Arguments | Passing values to functions |
*args |
Accepting variable-length positional arguments |
**kwargs |
Accepting variable-length keyword arguments |
| Combining Parameters | Using different parameter types together |
| Positional-Only and Keyword-Only Parameters | Controlling how arguments are passed |
| Argument Unpacking | Passing collection values as separate arguments |
| Return Values | Sending a result back from a function |
Learning Path: Python Function Parameters, Arguments and Return Values
The learning path below starts with the basics of parameters and arguments, then gradually moves through different ways of passing values to functions and ends with returning values from functions.
Topic 1: Parameters and Arguments in Python
Parameters define the inputs a function can accept, while arguments are the values passed to those parameters when the function is called.
Start with the basics of parameters and arguments before exploring more advanced ways of passing values to functions.
Learn More: Parameters and Arguments
Topic 2: Combining Different Types of Parameters
Python allows different types of parameters to be used in the same function. However, they must follow specific ordering and calling rules.
Learn how different parameter types can be combined and how Python applies these rules.
Learn More: Combining Function Parameters
Topic 3: Positional-Only and Keyword-Only Parameters
Python can restrict how certain parameters are passed to a function. Positional-only parameters must be passed by position, while keyword-only parameters must be passed using their parameter names.
Learn More: Positional-Only & Keyword-Only
Topic 4: Variable-Length Arguments: *args and **kwargs
Sometimes a function needs to accept a variable number of arguments. Python provides *args and **kwargs for these situations.
4A. *args — Variable-Length Positional Arguments
The *args parameter allows a function to accept any number of positional arguments and collects them into a tuple.
Learn More:
Python *args
4B. **kwargs — Variable-Length Keyword Arguments
The **kwargs parameter allows a function to accept any number of keyword arguments.
Learn More:
Python **kwargs
Topic 5: Argument Unpacking
Arguments can also be unpacked when calling a function. This allows values stored in a sequence or mapping to be passed as separate arguments.
Learn More: Argument Unpacking
Topic 6: Returning Values From Functions
After a function receives its arguments and performs its task, it can send a result back to the calling code using the return statement.
Learn More: Python Return Values
These topics provide a clear foundation for working with Python function parameters, arguments, and return values, from basic function calls to more advanced ways of passing and returning data.