The pythonic approach

Alex Martelli aleaxit at yahoo.com
Wed Sep 15 19:30:30 CEST 2004


Steven Bethard <steven.bethard at gmail.com> wrote:
   ...
> I actually wrote code not too long ago that did make a call like .get(x, x).

I consider somedict.get(x, x) a _frequent_ Python idiom!

translate_some_tags = dict(
    application='literal',
    foobar='barfoo',
    whatever='somethingelse',
    }

def translate_tag(tagName, attributes_dict):
    if tagName == 'emphasis' and attributes.get('role')=='bold':
        return 'bold'
    else:
        return translate_some_tags.get(tagName, tagName)

Isn't that a pretty frequent idiom when doing some minor massaging of
XML markup, for example?  (Spare me the passionate defenses of XSLT
please... I'm happy to use XSLT when warranted, but a lot of the XML
processing I do, and I _do_ do a lot of that, is in
Python+pulldom...!-).

> back.  I didn't have a function for it in my code, but I don't see why a
> function like:
> 
> def getstem(self, word):
>     return self.stemdict.get(word, word)
> 
> would be so unreasonable.

A very good idea!  If tomorrow you need to specialcase something, based
e.g. on RE's, you stick those into getstem (just like I do in
translate_tag for the few cases where a tag's translation may depend on
its attributes), and Bob's your uncle.  MUCH better than spreading calls
to get(word,word) all over the place!!!


Alex



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