pythoncard-users

[Pythoncard-users] iterating over components

[Michael S. <mik...@ya...>]

Am I correct in assuming the code below is the
standard way of iterating over components?

for component in self.components.itervalues():
   do stuff

The following seems more intuitive to me.

for component in self.components:
   do stuff

However, this causes a KeyError exception because
__iter__ is not defined. Is it ambiguous as to what
self.components should iterate over? If this makes
sense, an option would be to alias __iter__ in
WidgetDict (model.py) to UserDict.UserDict.itervalues.


Michael

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Re: [Pythoncard-users] iterating over components

[Andy T. <an...@ha...>]

Michael Sorich wrote:
> Am I correct in assuming the code below is the
> standard way of iterating over components?
> 
> for component in self.components.itervalues():
>    do stuff
> 
> The following seems more intuitive to me.
> 
> for component in self.components:
>    do stuff
> 
> However, this causes a KeyError exception because
> __iter__ is not defined. Is it ambiguous as to what
> self.components should iterate over? If this makes
> sense, an option would be to alias __iter__ in
> WidgetDict (model.py) to UserDict.UserDict.itervalues.
> 
> 
> Michael
> 

Michael,

You are correct. Because the components are an instance of WidgetDict 
from model.py and this inherits from UserDict.UserDict there is no 
__iter__ method. I'd say that the standard way of iterating over your 
components would be;

for component in self.components.keys():
     do stuff

To make the WidgetDict more like a standard dictionary the __iter__ 
method should return the key values and maybe we should look at 
implementing this. Does anyone have strong opinions either way?

Regards,
Andy
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