Periksa tipe nilai kembalian

Fleksibilitas Python terkait tipe data biasanya disebut sebagai salah satu keunggulan bahasa ini. Namun, kadang hal tersebut dapat menimbulkan masalah jika tipe data yang keliru tidak terdeteksi. Anda memutuskan bahwa, untuk memastikan kode Anda melakukan tepat seperti yang Anda inginkan, Anda akan secara eksplisit memeriksa tipe nilai kembalian di semua fungsi dan memastikan fungsi tersebut mengembalikan apa yang Anda harapkan. Untuk itu, Anda akan membuat sebuah dekorator yang memeriksa apakah tipe nilai kembalian dari fungsi yang didekorasi sudah benar.

Catatan: assert adalah sebuah kata kunci yang dapat Anda gunakan untuk menguji apakah sesuatu bernilai benar. Jika Anda mengetik assert condition dan condition bernilai True, fungsi ini tidak melakukan apa pun. Jika condition bernilai False, fungsi ini akan memunculkan sebuah error. Jenis error yang dimunculkan disebut AssertionError.

Latihan ini adalah bagian dari kursus

Menulis Function di Python

Latihan interaktif praktis

Cobalah latihan ini dengan menyelesaikan kode contoh berikut.

def returns_dict(func):
  # Complete the returns_dict() decorator
  def wrapper(____):
    result = ____
    assert type(result) == dict
    return result
  ____
  
@returns_dict
def foo(value):
  return value

try:
  print(foo([1,2,3]))
except AssertionError:
  print('foo() did not return a dict!')

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 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

Latihan Saat Ini

Exercise 13: Kerja bagus!