A newbie question about some code

[Dave Angel]

Jim Qiu wrote:
> Hi everyone.
> I am reading a python library code and found something i can not understand.
> Please help!
>
> class Envelope(object):
>
>     def __init__(self,ta_info):
>         self.ta_info = ta_info
>
>
>     def writefilelist(self,ta_list,tofile):
>         for filename in ta_list:
>             fromfile = botslib.botsopendata(filename,
> 'rb',self.ta_info['charset'])
>             shutil.copyfileobj(fromfile,tofile)
>             fromfile.close()
>
>     def convertfilelist(self,ta_list):
>         return [botslib.botsgetabspathdata(filename) for filename in
> ta_list]
>
>
>
> class myxmlenvelop(Envelope):
>     def __init__(self,ta_info,ta_list):
>         ''' class for (test) xml envelope. There is no standardised
> XML-envelope!
>             writes a new XML-tree; uses places-holders for XML-files to
> include; real enveloping is done by ElementTree's include'''
>         self.ta_info = ta_info
>         self._openoutenvelope()
>         #~ self.out.put({'BOTSID':'root','xmlns:xi':"
> http://www.w3.org/2001/XInclude"})     #works, but attribute is not removed
> bij ETI.include
>         self.out.put({'BOTSID':'root'})
>         ta_list = self.convertfilelist(ta_list)
>         for filename in ta_list:
>             self.out.put({'BOTSID':'root'},{'BOTSID':'{
> http://www.w3.org/2001/XInclude}include','parse':"xml",'href':filename})
>         self.out.envelopewrite(self.out.root
>
>
> Please check the blue highlighted part,  I don't understand how the object
> get the property?
>
>
> Jim
>
>   
Now that you tell us you want to know where the out property is coming 
from, I can respond.

Clearly, you don't have the whole class listed here.  Where's the 
_openoutenvelop() method, for example?   I'd guess it creates the out 
attribute.  Since it gets called from __init__(), and before the 
reference to self.out, that's what makes the most sense.