Python Decorators Overview

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson
Download our mobile app to listen on the go
Get App

Questions and Answers

What symbol is used in Python to apply decorators to a function?

  • #
  • %
  • &
  • @ (correct)

What is necessary when defining a decorator that takes arguments?

  • 1.2 (correct)
  • 1.1
  • 1.4
  • 1.3

Which of the following allows a decorator to accept any number of arguments?

  • Only using fixed arguments
  • Defining a function without parameters
  • Using a single argument
  • Using *args and **kwargs (correct)

What must be passed to a decorator function when using decorators in Python?

<p>A function (B)</p> Signup and view all the answers

Why would someone use a general purpose decorator?

<p>To apply the same behavior to multiple functions (B)</p> Signup and view all the answers

What is the primary purpose of a decorator in Python?

<p>To add new functionality to an existing function (A)</p> Signup and view all the answers

How are decorators typically applied in Python?

<p>Before the function definition (A)</p> Signup and view all the answers

What best describes 'first class citizens' in Python concerning functions?

<p>Functions can be passed as arguments and returned from other functions (D)</p> Signup and view all the answers

What is another term for inner functions that are used in decorators?

<p>Wrapper functions (B)</p> Signup and view all the answers

What ability allows a nested function to access the outer enclosing function in Python?

<p>Scope inheritance (D)</p> Signup and view all the answers

When creating a basic decorator to capitalize each word in a sentence, which of the following is essential?

<p>Implementing a wrapper function within an outer function (A)</p> Signup and view all the answers

What is a key characteristic of functions in Python regarding their structure?

<p>Functions can be assigned to variables and modified (C)</p> Signup and view all the answers

What happens when a function is wrapped by a decorator?

<p>The original function remains unchanged and is executed as usual (C)</p> Signup and view all the answers

Flashcards

Decorator functions

Decorator functions are functions that take another function as input and return a new function. They modify the behavior of the input function.

Python decorator syntax

Python provides a shortcut using the '@' symbol to apply decorators. The @ symbol precedes the function you want to decorate.

Decorators with arguments

Decorators can accept arguments which are then passed to the inner wrapper function. These arguments are used during the decorated function's call.

General-purpose decorators

These decorators can be applied to any function and can accept any number of arguments using *args and **kwargs.

Signup and view all the flashcards

Exercises on functions and decorators

Practice exercises for functions and decorators are available in the learning platform (Moodle). These provide hands-on experience with the concepts covered.

Signup and view all the flashcards

Decorator in Python

A design pattern enhancing existing objects (typically functions) without altering their structure, adding functionality.

Signup and view all the flashcards

First-Class Function (Python)

Functions treated like data in Python; can be passed as arguments, returned from functions, assigned to variables, or modified.

Signup and view all the flashcards

Wrapper Function

A function nested (defined inside) another function, used to modify behavior of the outer function.

Signup and view all the flashcards

Nested function access

Inner functions (wrapper) can access variables and attributes in the outer function's scope.

Signup and view all the flashcards

Decorator application

Decorators are placed before the function definition to be enhanced.

Signup and view all the flashcards

Function as argument

Passing a function as input to other functions for modification or execution.

Signup and view all the flashcards

Function returning a function

A function can be the output of another function. This is valuable in decorators to enhance functions.

Signup and view all the flashcards

Capitalizing a sentence

Transformation of a sentence to uppercase. Example: 'hello world' to 'Hello World'.

Signup and view all the flashcards

Study Notes

Python Decorators

  • Decorators are design patterns enhancing existing objects (typically functions) without altering their structure.
  • They significantly impact function behavior, adding functionalities.
  • Positioned before the function definition needing modification.
  • Python functions are first-class citizens, enabling their use as arguments, return values, assignment to variables, and modification.
  • This flexibility allows functions to be treated like general objects.

Decorator Example

  • A plus_one function adds 1 to a given number.
  • Assigning the function to a variable (add_one = plus_one) allows calling the original function through the alias.
  • add_one(5) results in 6.

Inner Functions/Wrapper Functions

  • Functions can be nested within other functions.
  • Sometimes, inner functions are called wrapper functions.

Decorators Accepting Arguments

  • Decorators can accept arguments, which are passed to the wrapper function.
  • These arguments then get transferred to the original function which is being decorated.

General Purpose Decorators

  • Decorators can adapt to any function.
  • *args and **kwargs allow multiple argument handling.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Python Decorators Lecture Notes PDF

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser