__clousre__ : Usecase 정리

closure

def return_a_func(arg1, arg2):
  def new_func():
    print('arg1 was {}'.format(arg1))
    print('arg2 was {}'.format(arg2))
  return new_func
    
my_func = return_a_func(2, 17)

print(my_func.__closure__ is not None)

# Show that there are two variables in the closure
print(len(my_func.__closure__) == 2)

def return_a_func(arg1, arg2):
  def new_func():
    print('arg1 was {}'.format(arg1))
    print('arg2 was {}'.format(arg2))
  return new_func
    
my_func = return_a_func(2, 17)

print(my_func.__closure__ is not None)
print(len(my_func.__closure__) == 2)

# Get the values of the variables in the closure
closure_values = [
  my_func.__closure__[i].cell_contents for i in range(2)
]
print(closure_values == [2, 17])

# Decorate my_function() with the print_args() decorator
@print_args
def my_function(a, b, c):
  print(a + b + c)

my_function(1, 2, 3)

def print_before_and_after(func):
  def wrapper(*args):
    print('Before {}'.format(func.__name__))
    # Call the function being decorated with *args
    func(*args)
    print('After {}'.format(func.__name__))
  # Return the nested function
  return wrapper

@print_before_and_after
def multiply(a, b):
  print(a * b)

multiply(5, 10)