(Replying to Greg, though his original message doesn't appear at Gmane.)
> Greg Lindstrom <gslindst...@gmail.com> writes:
>
> > I am working on a project where I'm using dictionaries to hold the
> > translations to codes (i.e., {'1':'Cheddar','2':'Ice
> > Hockey','IL':'Thermostat Broken'}). The bulk of the application
> > requires me to translate codes to their meaning, but it would be nice
> > to be able to translate a meaning back to the original code as
> > well.
If the dict is small and static, and you are sure that each value is
unique, I would say simply create the reverse mapping::
desc_by_code = {
'1': "Cheddar",
'2': "Ice Hockey",
'IL': "Thermostat Broken",
}
code_by_desc = dict(
(desc, code) for (code, desc) in codes_to_messages.items())
> > This seems to me like it must be a common situation that has been
> > addresses/solved by those smarter than me. Is there, dare I say, a
> > design pattern for this problem?
Yes, a relational database. That might be too much overhead though.
> > Is there a better way of approaching
> > it other than making a set of dictionaries which "mirror" the
> > originals? FWIW, I have approximately 50 tables ranging from 2
> > entries to over 100.
You may have crossed the threshold where a relational database becomes
more useful than a bunch of dicts. SQLite is built into Python, and can
store its database in memory or in a single file.
If the overhead of a database layer is too much, then creating the
reverse mappings automatically (as above) is simple enough and works
fine.
--
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_o__) once and for all.” —Daniel Dennett, 2010-01-12 |
Ben Finney
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