How do we use *args and **kwargs with decorators

Question

i don't get why are we doing that args[0]["valid"] instead of just args["valid"]

 user1 = {
    'name': 'Sorna',
    'valid': True
}

def authenticated(fn):
  def wrapper(*args, **kwargs):
    if args[0]['valid']== True: #if args['valid']== True:
        return fn(*args, **kwargs)
  return wrapper

@authenticated
def message_friends(user):
    print('message has been sdent')

message_friends(user1)

Answer 1

*args are always passed as tuple, so you need to use an index to access the contents:

def authenticated(fn):
  def wrapper(*args, **kwargs):
    print('A', args)
    print('K', kwargs)
    if args[0]['valid']== True:
        return fn(*args, **kwargs)
  return wrapper

Out:

A ({'name': 'Sorna', 'valid': True}, )
K {}

Alternatively, you could pass user1 as kwargs to get rid of the indexes:

def authenticated(fn):
  def wrapper(*args, **kwargs):
    print('A', args)
    print('K', kwargs)
    if kwargs['valid']== True:
        return fn(*args, **kwargs)
  return wrapper

@authenticated
def message_friends(**user):
    print('message has been sent to %s' % user['name'])

message_friends(**user1)

Out:

A ()
K {'name': 'Sorna', 'valid': True}
message has been sent to Sorna