[Tutor] Key Error

[Bob Gailer]

Sara Johnson wrote:
>  
> Probably best if I skip the example and show what code I do have:
> ~~~~~~~~~~~
> for key in h.keys():
>         wssd=h[key]['WSSD']
>         wspd=h[key]['WSPD']
>         wmax=h[key]['WMAX']
>         newi=h[key]['NEWI']
>         if wssd<-989. or wspd<-989. or wmax<-989.: break
>         if wspd==0.: break
> ~~~~~~~~~~~~~~~~~
> Where the "newi" = "abcd" that I showed before.  I have no where else 
> in my code anything pertaining to these 4 keys.  The first 3 were 
> there, and produce no errors.  I am making adjustments to an existing 
> script.  I only have C programming knowledge so my thought was that it 
> "newi" was just a variable that needed to be assigned.  You'll notice 
> the parameters below (i.e., if wssd < -989 ) but there is obviously 
> nothing for "newi" at the moment.  The program's only error at the 
> moment seems to be this line:
>  
>  newi=h[key]['NEWI']
> But as you can see, the other items are set up the same way.
Most likely h is a dictionary, and the values are also dictionaries. At 
least one of the value dictionaries has no key "NEWI".
To see what h is, put:
print h
before the for statement. You should see something like:
{'somekey': {'WSSD': 3, 'WSPD': 4, 'WMAX': 5, 'NEWI': 6}, 'anotherkey': ...}
Python uses braces with key : value pairs to represent a dictionary.
If that does not help you, post the result (or attach if it is really long).

Then we need to find how h itself was created. Any clues about that?

-- 
Bob Gailer
510-978-4454 Oakland, CA
919-636-4239 Chapel Hill, NC