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Functions
In programming, a function is a reusable block of code that executes a certain functionality when it is called. Functions are integral parts of every programming language because they help make your code more modular and reusable.
In Python, you define a function with the def keyword, then write the function identifier (name) followed by parentheses and a colon.
Visit the following resources to learn more:
- @article@Python Functions – How to Define and Call a Function
- @article@Python Functions - W3Schools
- @article@Built-in Functions in Python
| Function Type | Syntax Example | Description | Characteristics | Use Case |
|---|---|---|---|---|
| Regular Function | def func_name(params): | Defines a function with a name and optional parameters. | Can have default parameters, return values. | General-purpose functions. |
| Lambda Function | lambda params: expression | Defines a small anonymous function, typically used for short, simple operations. | Single expression, no statements, returns result. | Quick, inline operations, often in map, filter. |
| Generator Function | def func_name(params): <br> yield value | A function that returns an iterator and uses yield to produce a sequence of values lazily. | Maintains state, can be iterated over. | Generating large sequences without storing them in memory. |
| Recursive Function | def func_name(params): <br> func_name() | A function that calls itself to solve a problem by breaking it down into smaller subproblems. | Must have a base case to avoid infinite recursion. | Tasks like traversing data structures, solving problems that can be broken down into similar subproblems. |
| Higher-Order Function | def func_name(func): <br> return func | A function that takes one or more functions as arguments or returns a function. | Functions can be passed as arguments or returned. | Functional programming, callbacks, decorators. |
| Built-in Function | len(), print(), range() | Functions that are built into Python and available without importing any modules. | Directly accessible, part of Python’s standard library. | Common tasks like printing, measuring length, iterating. |
| Decorated Function | @decorator <br> def func_name(params): | A function that is modified by a decorator, which adds functionality before or after the function. | Allows cross-cutting concerns like logging, access control. | Enhancing or modifying the behavior of functions. |
| Coroutine Function | async def func_name(params): | Defines an asynchronous function that can use await to pause and resume execution. | Runs asynchronously, works with event loops. | Concurrency, non-blocking I/O operations. |
| Method (Instance Method) | def method_name(self, params): | A function defined within a class that operates on an instance of the class. | Requires self parameter, called on instances. | Operating on data within an object, instance-specific behavior. |
| Class Method | @classmethod <br> def method_name(cls, params): | A function that operates on the class itself rather than instances of the class. | Requires cls parameter, called on class. | Factory methods, methods that affect the class as a whole. |
| Static Method | @staticmethod <br> def method_name(params): | A function within a class that does not operate on instances or the class itself. | No self or cls parameter, called on class. | Utility functions related to a class but not dependent on instance or class data. |
| Magic Method | def __init__(self, params): | Special methods with double underscores used for operator overloading and object behavior. | Follow __methodname__ naming convention. | Overloading operators, defining object behavior (e.g., __str__, __add__). |