From dictionary keys to variables

Jeff Shannon jeff at
Tue Oct 12 03:55:52 CEST 2004

Michael Foord wrote:

>I use a module called COnfigObj to read my config files into python.
>It exposes them as a dictionary.
>I often find myself writing code like :
>valuelist = ['name1', 'name2', 'name3'....]
>config = ConfigObj(filename, configspec=valuelist)
>name1 = config['name1']
>name2 = config['name2']
>name3 = config['name3']

Any reason why it's necessary to define variables instead of just using 
the dict?  You're probably not really saving anything by doing this...  
there *might* be a slight savings in typing if you use the names 
numerous times, but directly accessing the dictionary makes it clearer 
where your values are coming from.  And dict lookups are fast, so unless 
you're using these valuables repeatedly inside a tight loop, you won't 
get significant speed savings.  (If you *are* using some inside a tight 
loop, then it's sensible to hoist the lookup out of the loop, but don't 
do this until you know that that loop is a significant source of 
slowdown -- as they say, premature optimization is the root of all evil.)

Jeff Shannon
Credit International

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