Answers for "what is python decorator"

decorator python

def our_decorator(func):
    def function_wrapper(x):
        print("Before calling " + func.__name__)
        func(x)
        print("After calling " + func.__name__)
    return function_wrapper

@our_decorator
def foo(x):
    print("Hi, foo has been called with " + str(x))

foo("Hi")

python decorator

#Decorator are just function that take function as first
#parameter and return a function
def logging(f):
  def decorator_function(*args, **kwargs):
    print('executing '+f.__name__)
    return f(*args, **kwargs)
  return decorator_function
#Use it like this
@logging
def hello_world():
  print('Hello World')
#calling hello_world() prints out:
#executing hello_world
#Hello World

decorators in python

#This function take user input for list and returns a tuple cotaining 2 lists
#one of even numbers another of odd numbers
def deco(function):
    def wrap(lst):
        even = []
        odd = []
        for i in lst:
            if i % 2 == 0:
                even.append(i)
            else:
                odd.append(i)
        return even,odd
        function(lst)
    return wrap

@deco
def display(lst):
    print(lst)


a = [int(x) for x in input("Enter number of elements : ").split(",")]
print(display(a))

python decorator

# Decorator with arguments
import functools

# First function takes the wanted number of repetition
def repeat(num_times):
    # Second function takes the function
    def decorator_repeat(func):
        # Third function, the wrapper executes the function the number of times wanted        
        # functools decorator to print the true name of the function passed instead of "wrapper"
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            for _ in range(num_times):
                result= func(*args, **kwargs)
            return result
        return wrapper
    return decorator_repeat

# Our function using the decorator
@repeat(num_times= 3)
def greet(name):
    print(f"Hello {name}")

greet("thomas")

decorators in python

# This function take input from user and return
# list of 0 and 1, zero represents odd number
# and 1 represents even number
def deco(func):
    def wrap(lst):
        x = [1 if i % 2 == 0 else 0 for i in lst]
        return x
        func(lst)
    return wrap

@deco   
def display(l):
    return (l)

a = [int(x) for x in input("Enter number of elements : ").split(",")]
print(display(a))