Cetak tipe nilai kembalian

Anda sedang men-debug sebuah paket yang Anda kerjakan bersama teman-teman. Ada sesuatu yang aneh pada data yang dikembalikan oleh salah satu fungsi Anda, tetapi Anda bahkan belum yakin fungsi mana yang menyebabkan masalah. Anda tahu bahwa bug kadang dapat menyelinap ketika Anda mengharapkan sebuah fungsi mengembalikan satu jenis nilai, tetapi ternyata mengembalikan jenis yang berbeda. Misalnya, jika Anda mengharapkan fungsi mengembalikan array numpy, tetapi malah mengembalikan list, perilaku yang tidak terduga dapat terjadi. Untuk memastikan hal ini bukan penyebab masalah, Anda memutuskan menulis sebuah dekorator, print_return_type(), yang akan mencetak tipe variabel yang dikembalikan dari setiap pemanggilan fungsi apa pun yang dihias olehnya.

Latihan ini adalah bagian dari kursus

Menulis Function di Python

Petunjuk latihan

Buat fungsi bersarang, wrapper(), yang akan menjadi fungsi baru yang didekorasi.
Panggil fungsi yang didekorasi.
Kembalikan fungsi baru yang didekorasi.

Latihan interaktif praktis

Cobalah latihan ini dengan menyelesaikan kode contoh berikut.

def print_return_type(func):
  # Define wrapper(), the decorated function
  ____ ____(____, ____):
    # Call the function being decorated
    result = ____(____, ____)
    print('{}() returned type {}'.format(
      func.__name__, type(result)
    ))
    return result
  # Return the decorated function
  return ____
  
@print_return_type
def foo(value):
  return value
  
print(foo(42))
print(foo([1, 2, 3]))
print(foo({'a': 42}))

Edit dan Jalankan Kode

Latihan ini adalah bagian dari kursus

Menulis Function di Python

SkillTag.level.intermediateSkillTag.label

4.8+

Mulai Kursus Gratis

The goal of this course is to transform you into a Python expert, and so the first chapter starts off with best practices when writing functions. You'll cover docstrings and why they matter and how to know when you need to turn a chunk of code into a function. You will also learn the details of how Python passes arguments to functions, as well as some common gotchas that can cause debugging headaches when calling functions.

Exercise 1: Docstrings Exercise 2: Crafting a docstring Exercise 3: Retrieving docstrings Exercise 4: Docstrings to the rescue!Exercise 5: DRY and "Do One Thing"Exercise 6: Extract a function Exercise 7: Split up a function Exercise 8: Pass by assignment Exercise 9: Mutable or immutable?Exercise 10: Best practice for default arguments

If you've ever seen the "with" keyword in Python and wondered what its deal was, then this is the chapter for you! Context managers are a convenient way to provide connections in Python and guarantee that those connections get cleaned up when you are done using them. This chapter will show you how to use context managers, as well as how to write your own.

Exercise 1: Using context managers Exercise 2: The number of cats Exercise 3: The speed of cats Exercise 4: Writing context managers Exercise 5: The timer() context manager Exercise 6: A read-only open() context manager Exercise 7: Advanced topics Exercise 8: Context manager use cases Exercise 9: Scraping the NASDAQ Exercise 10: Changing the working directory

Decorators are an extremely powerful concept in Python. They allow you to modify the behavior of a function without changing the code of the function itself. This chapter will lay the foundational concepts needed to thoroughly understand decorators (functions as objects, scope, and closures), and give you a good introduction into how decorators are used and defined. This deep dive into Python internals will set you up to be a superstar Pythonista.

Exercise 1: Functions are objects Exercise 2: Building a command line data app Exercise 3: Reviewing your co-worker's code Exercise 4: Returning functions for a math game Exercise 5: Scope Exercise 6: Understanding scope Exercise 7: Modifying variables outside local scope Exercise 8: Closures Exercise 9: Checking for closure Exercise 10: Closures keep your values safe Exercise 11: Decorators Exercise 12: Using decorator syntax Exercise 13: Defining a decorator

Now that you understand how decorators work under the hood, this chapter gives you a bunch of real-world examples of when and how you would write decorators in your own code. You will also learn advanced decorator concepts like how to preserve the metadata of your decorated functions and how to write decorators that take arguments.

Exercise 1: Contoh dunia nyata Exercise 2: Cetak tipe nilai kembalian

Latihan Saat Ini

Exercise 3: Penghitung Exercise 4: Decorator dan metadata Exercise 5: Mempertahankan docstring saat mendekorasi fungsi Exercise 6: Mengukur overhead dekorator Exercise 7: Dekorator yang menerima argumen Exercise 8: Run_n_times()Exercise 9: Generator HTML Exercise 10: Timeout(): contoh dunia nyata Exercise 11: Beri tag pada fungsi Anda Exercise 12: Periksa tipe nilai kembalian Exercise 13: Kerja bagus!