[Tutor] decorators

[Prasad, Ramit]

Excellent explanation Steven; I understood the mechanical basics but this has made the reason behind it a lot clearer. 

If test_argument is only being passed the function how does it have access to the arguments? Or is that more syntactic sugar / abbreviation for explanation?

def test_argument(func):
     def inner(arg):
         if not (isinstance(arg, int) and arg > 0):
             raise ValueError('bad argument')
         arg = min(arg, 1000)
         return func(arg)
     return inner


@test_argument
def func(arg):
     do stuff

This communication is for informational purposes only. It is not
intended as an offer or solicitation for the purchase or sale of
any financial instrument or as an official confirmation of any
transaction. All market prices, data and other information are not
warranted as to completeness or accuracy and are subject to change
without notice. Any comments or statements made herein do not
necessarily reflect those of JPMorgan Chase & Co., its subsidiaries
and affiliates.

This transmission may contain information that is privileged,
confidential, legally privileged, and/or exempt from disclosure
under applicable law. If you are not the intended recipient, you
are hereby notified that any disclosure, copying, distribution, or
use of the information contained herein (including any reliance
thereon) is STRICTLY PROHIBITED. Although this transmission and any
attachments are believed to be free of any virus or other defect
that might affect any computer system into which it is received and
opened, it is the responsibility of the recipient to ensure that it
is virus free and no responsibility is accepted by JPMorgan Chase &
Co., its subsidiaries and affiliates, as applicable, for any loss
or damage arising in any way from its use. If you received this
transmission in error, please immediately contact the sender and
destroy the material in its entirety, whether in electronic or hard
copy format. Thank you.

Please refer to http://www.jpmorgan.com/pages/disclosures for
disclosures relating to European legal entities.