calling a class instance of function

[Pyenos]

class pid:
"pid"
def add(original_pid,toadd):
"add pid"
original_pid.append(toadd)
return original_pid
def remove(something_to_remove_from,what):
"remove pid"
something_to_remove_from.remove(what)
return something_to_remove_from
def modify(source,element,changewiththis):
"modify pid"
source[source.index(element)]=changewiththis
return source

class test(pid):
pid.original=[1,2,3]
pid.toadd=4
pid.add(pid.original,pid.toadd) # error here says that
# it expects pid instance as first arg
# not a list that it got.

why do i get an error?

[Brett Hoerner]

Pyenos wrote:

class test(pid):
pid.original=[1,2,3]
pid.toadd=4
pid.add(pid.original,pid.toadd) # error here says that
# it expects pid instance as first arg
# not a list that it got.

why do i get an error?

'test' is a class here, and the pid you tried to pass it is actually
the class it is inheriting from. I think you wanted to do:

def test(pid):
...

Also, in order to call a function without arguments you still need to
use (), so you probably wanted to use pid.original() in your pid.add
call.

Brett Hoerner

[Brett Hoerner]

Brett Hoerner wrote:

Also, in order to call a function without arguments you still need to
use (), so you probably wanted to use pid.original() in your pid.add
call.

Sorry, never mind this bit, I misread the line. But you do probably
want to change the class test into a function test.

Brett Hoerner

[Gabriel Genellina]

On 20 dic, 21:09, Pyenos <[e-mail]:

class pid:
"pid"
def add(original_pid,toadd):
"add pid"
original_pid.append(toadd)
return original_pid

For a method, you have to include an *explicit* first parameter
(usually called "self") that refers to the instance on which you call
the method (like "this" on other languages, but you have to be explicit
in Python).
Read the Python tutorial: http://docs.python.org/tut/

--
Gabriel Genellina

[=?iso-8859-1?Q?=22Nils_Oliver_Kr=F6ger=22?=]

Hi,

Methods i.e functions bound to a class instance (or object) the self argument in their definition:

class pid:
def add(self, toadd):
pass #or some sensible code
 

If you want to define a method without that implicit self argument you'll have to make this method a static:

class pid:
@staticmethod
def staticadd (param1, param2):
pass #or some sensible code
 

Furthermore, your test() seems to be rather a function than a class:
You want to use this function to test the pid class but what you do with your code below is to define a class test which inherits pid. I'm not really sure what the following lines do ... this would usually be the place to introduce class variables.

Hope that Helps!

Greetings

Nils

-------- Original-Nachricht --------
Datum: 21 Dec 2006 11:09:32 +1100
Von: Pyenos <py****@pyenos.org>
An: py*********@python.org
Betreff: calling a class instance of function

>
class pid:
"pid"
def add(original_pid,toadd):
"add pid"
original_pid.append(toadd)
return original_pid
def remove(something_to_remove_from,what):
"remove pid"
something_to_remove_from.remove(what)
return something_to_remove_from
def modify(source,element,changewiththis):
"modify pid"
source[source.index(element)]=changewiththis
return source

class test(pid):
pid.original=[1,2,3]
pid.toadd=4
pid.add(pid.original,pid.toadd) # error here says that
# it expects pid instance as first arg
# not a list that it got.

why do i get an error?
--
http://mail.python.org/mailman/listinfo/python-list

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