While we're on this kind of topic what is the best approach in python to
creating code macros? That is ability to write a higher level language
(or script) which translates down into python? Decorators look like they
would be part of that story. Is that the best way or is their a more
general way?
Thanks,
Lin
p.s. I used to write code macros in LISP... context I am coming from.
----- Original Message ----- From: "Michael George"
<mdgeorge@xxxxxxxxxxxxxx>
To: <pygame-users@xxxxxxxx>
Sent: Wednesday, December 31, 2008 9:56 AM
Subject: Re: [pygame] @
Michael Phipps wrote:
Yanom -
A decorator is a method that takes another method as a parameter so
that it can do something. It is usually used for aspect oriented
programming.
For example:
def logThisMethodCall(methodCall)
# Do some logging here
@logThisMethodCall
def myMethod(a,b,c)
# do Somthing in here
Now, whenever you call "myMethod", logThisMethodCall gets called
first, with the invocation of myMethod passed into it. You can use it
for logging, security (i.e. does this person have permission to be
calling this), etc.
Michael
This isn't quite right. logThisMethodCall doesn't get called when you
call myMethod, but when you _define_ myMethod. So to fix this example:
def logThisMethodCall(methodCall):
def result(a,b,c):
# do some logging here
methodCall(a,b,c)
return result
@logThisMethodCall
def myMethod(a,b,c):
# do something here
When you define myMethod, logThisMethodCall is called to create a
replacement function for myMethod. it returns a new function "result"
which gets called instead of the original myMethod whenever someone
calls myMethod. result does some logging and then calls the orginal
myMethod.