On 1/06/2006 9:24 AM, 3rdshiftcoder wrote:
> hi-
>
> i am having trouble using parameter values in my function and to be honest a
> little trouble with
> member variables. i am trying to pass in the argument 'd' representing
> delete.
> what the code will do is if it is 'd' it will make a delete query template
> string.
> if it is an 'i' then insert query etc.
>
> this is the results of my attempt to print the contents of the parameter
> values.
> <__main__.getQryStr instance at 0x01151D50> ('d',) me mad
Exactly right, first parameter is the object itself, second parameter is
a 1-tuple of the supplied args. See more explanation below.
>
>
> (and on a side note if i dont include the *args i get an invalid number of
> parameters supplied message.)
> why is it returning the value in this format ('d',) ?
> i cant get x == d
> i guess that value 'd' is stored in a tuple and i'd like to get it out of
> there.
No, 'd' is stored as the value of the attribute you've named "x". One of
the main points of the whole OO caper is that objects have attributes --
please see later remarks about the tutorial.
>
> so basically the function returns nope as it stands
>
> python is sure different from other languages i have used.
>
> thanks for any help,
> jim
>
>
> class getQryStr:
> def __init__(self,op):
> print op
> self.x = 'd'
You probably meant
self.x = op
> def returnStr(x,*args):
Like the first (__init__) method, this should have the mandatory "self"
argument, plus *one* other arg .. *if* you need it. It's not apparent
why you are calling the constructor *and* the returnStr method *each*
with 'd'.
>
> print '%s %s me mad' % (x,args)
> if x == 'd':
Here x is the object that you have created. The first argument to a
method is the object itself, and is conventionally named "self". It must
be declared in the method itself
def amethod(self, arg1, arg2):
but is supplied automatically when you invoke it
anobj.amethod('foo', 42)
[snip]
Please consider working your way through the Python tutorial
http://docs.python.org/tut/node11.html
and/or one of the free e-books e.g.
http://www.byteofpython.info/
At the end of this post is a modified version of your script which shows
what is going on under normal expected usage.
HTH,
John
8<=== demo script ===
C:\junk>type use_self.py
class getQryStr:
def __init__(self, op):
print '__init__ ... op:%r' % op
self.x = op
def returnStr(self, arg):
print 'returnStr ... self.x:%r arg:%r' % (self.x, arg)
return '=%s=%s=' % (self.x, arg)
obj = getQryStr('blah')
print '__main__ ... obj.x:%r' % obj.x
s = obj.returnStr('yadda')
print '__main__ ... s:%r' % s
8<=== output from demo script ===
C:\junk>use_self.py
__init__ ... op:'blah'
__main__ ... obj.x:'blah'
returnStr ... self.x:'blah' arg:'yadda'
__main__ ... s:'=blah=yadda='
8<=== end ===
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