Donn -
The thing you are lacking is the use of pyparsing's lookahead class,
FollowedBy. In this case, you want to detect the difference between a
single (which I have redefined as just "simple | quoted", and let the query
expression take care of the repetition) and a field identifier. In this
case, you want a negative lookahead of ~FollowedBy(":").
single = simple | quoted
COLON = PP.Suppress(':')
fieldValue = single + ~PP.FollowedBy(COLON)
field = single + COLON + PP.Group(PP.OneOrMore(fieldValue))
phrase = fieldValue
phrases = PP.ZeroOrMore(phrase)
query = PP.Optional(phrases) + PP.ZeroOrMore(field)
To add the dict-style access to the fields, add some results names, and use
the Dict class to auto-define results names for each field name.
query = PP.Optional(phrases)("phrases") +
PP.Dict(PP.ZeroOrMore(PP.Group(field)))("fields")
Keep plugging!
-- Paul
> -----Original Message-----
> From: Donn Ingle [mailto:don...@gm...]
> Sent: Sunday, June 07, 2009 3:46 AM
> To: pyp...@li...
> Subject: [Pyparsing] Choppping up search terms
>
> Hello pyparsers.
> As much as pyparsing astounds my small mind, I have yet to write my own
> 'grammar' without having to ask for help! And here I am again. I hope
> someone will have mercy on me.
>
> I am adding a search function to Fonty Python and this starts with
> chopping-
> up a string into tokens. I have a simple set of rules:
>
> phrase1 phrase2 field: value1 value2 "value three" field2: value1 etc
>
> Any word on it's own if it's NOT after a fieldname is a phrase alone.
> Anything after a fieldname is a sub-phrase of that field, unless it's
> another fieldname.
>
> I am just not getting anything like what I am looking for.
> \d
>
> My hacking and surfing and re-hacking have ended here:
>
> import pyparsing as PP #testing with vers 1.4.8 and 1.5.0
>
> simple = PP.Word(PP.alphas)
> quoted = PP.dblQuotedString.setParseAction(PP.removeQuotes)
> single = PP.OneOrMore(simple | quoted)
> special = PP.Combine(PP.Word(PP.alphas) + ":") + single
>
> #term = special | single
> query = PP.OneOrMore( special | single )# + PP.StringEnd() <- buggy
>
> tests=[
> u"WTF Huh aField: aValue",
> # want: [u'WTF', u'Huh', {u'aField:':[u'aValue']}]
> u'aField : "aValue blah" bloop AnotherField: two',
> # want: [{u'aField:':[u'aValue blah',u'bloop']},{u'AnotherField:':u'two'}]
> u"aField: Someval AnotherField: two"
> # want : [{u'aField:':[u'SomeVal']},{u'AnotherField:':u'two'}]
> ]
>
> for test in tests:
> print test
> try:
> tokens=query.parseString(test)
> print tokens
> except:
> print "BUG"
>
>
>
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