_winreg newbie question

[Joe Green]

Duncan Booth <duncan at NOSPAMrcp.co.uk> wrote in message news:<Xns936C72D87CE5Dduncanrcpcouk at 127.0.0.1>...
> the_3_project at yahoo.com (Joe Green) wrote in 
> news:a5b86892.0304290139.6870fb2b at posting.google.com:
> 
> >    if (key is "LOCAL_MACHINE"):
> 
> What do you think this line does? It doesn't compare two strings to see if 
> they are equal.
> 
> Perhaps you meant:
> 
>      if key == 'LOCAL_MACHINE':

YES! That's what I'm trying to do :)

> 
> The 'is' operator checks whether two expressions both result in exactly the 
> same object. This is not something you want to do very often.

Very well, thanks for the hint.

> Usually objects can be equal without being the same object. (You can use 
> 'is' to check whether an object 'is None' but that is because there is 
> guaranteed only to be one None object in the system.)
> 

Makes sense.

> Some other style points (feel free to disagree/ignore):

Oh no, this is very helpful stuff. However, I was trying to minimize
the code and put in a bare minimum to demonstrate the problem -- this
is not really how the real implementation looks.

> 
> Never use 'from <module> import *' unless the module documentation insists 
> you should (_tkinter does). It is likely to come back and bite you later.
> 

Ah.. yes, normally I don't. In cases such as this, I do because I know
there will not be conflicts.

> Get rid of the unnecessary parentheses in your 'if' statements. Python is 
> not C.
> 

They are for my sanity. I do come from a C++ background :) I don't
usually use them unless there are logical and's and or's in the if
statement. Again, this was just for the demonstration of the problem.

> There are several ways to avoid that unsightly list of if...elif 
> statements. Perhaps the easiest would be:
> 
>     def IterKeys(self, key, subkey=None):
>         regkey = getattr(self, key, None)
>         ...
> 
> and then use regkey in place of 'self.reg[mykey]'.
>  

Ah. Now that's something I can incorporate. Let's see how that works.

> Calling sys.exit when you cannot create the class seems a bit drastic. You 

Yeah of course, drastic measures were needed to emphasise :)

> might prefer to throw a more specific exception instead, or even just 

Right. That's what the actual implementation does.

> remove your try...except block and handle the exception at an outer level. 
> As a general point an except block that catches every exception should make 
> sure it does something useful (such as logging or displaying the error that 
> actually occurred).

I do both whenever possible. Did I say I come from a Linux background?
We like them logs :)

Thanks a lot!