Callbacks are where you send python (or a library) a function which it can
call(back). They are usually used to make things a little more generic.
Here's a (trying to make it simple) example.
######## example.py ###########
# These first three are callback functions (nothing special
# is needed to make them a callback function)
def printtoscreen(s):
print s
def printdifferently(s):
s = s.upper()
print s
def printtofile(s):
fobj = file("output.txt","a")
fobj.write(s)
fobj.close()
# this is the generic function that uses callbacks
def doPrint(s, callbackfunc):
callbackfunc(s)
# and then we can use it however we wish
# because doPrint never has to change
# no matter how, or to what we are printing.
doPrint("HelloWorld!", printtofile)
doPrint("Hello World!", printtoscreen)
doPrint("ascii", printdifferently)
##############################
----- Original Message -----
From: "Michael Bernhard Arp Sørensen" <[EMAIL PROTECTED]>
To: <tutor@python.org>
Sent: Saturday, December 29, 2007 10:58 AM
Subject: [Tutor] Learning about callbaks
Hi there.
I want to learn about callbacks because we use it at work in our software.
I there a short "hello world"-like version of a callback example?
--
Med venlig hilsen/Kind regards
Michael B. Arp Sørensen
Programmør / BOFH
I am /root and if you see me laughing you better have a backup.
--------------------------------------------------------------------------------
> _______________________________________________
> Tutor maillist - Tutor@python.org
> http://mail.python.org/mailman/listinfo/tutor
>
_______________________________________________
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
