Given a line -
f = "j = { line = { foo = 10 bar = 20 } }"
And given the following code -
select = pp.Forward()
select <<
pp.Word(pp.printables) + pp.Suppress("=") + pp.Suppress("{") +
pp.OneOrMore( (pp.Word(pp.printables) + pp.Suppress("=") +
pp.Word(pp.printables) ) | select ) + pp.Suppress("}")
sel.parseString(f) gives -
(['j', 'line', '{', 'foo', '10', 'bar', '20'], {})
So I've got a bracket sneaking through there. Argh. My brain hurts.
Is the | operator an exclusive or?
Befuddled,
Liam Clarke
On 7/23/05, Liam Clarke <[EMAIL PROTECTED]> wrote:
Howdy,
I've attempted to follow your lead and have started from scratch, I could just copy and paste your solution (which works pretty well), but I want to understand what I'm doing *grin*
However, I've been hitting a couple of ruts in the path to enlightenment. Is there a way to tell pyparsing that to treat specific escaped characters as just a slash followed by a letter? For the time being I've converted all backslashes to forwardslashes, as it was choking on \a in a file path.
But my latest hitch, takes this form (apologies for large traceback)
Traceback (most recent call last):
File "<interactive input>", line 1, in ?
File "parse.py", line 336, in parse
parsedEntries = dicts.parseString(test_data)
File "c:\python24\Lib\site-packages\pyparsing.py", line 616, in parseString
loc, tokens = self.parse( instring.expandtabs(), 0 )
File "c:\python24\Lib\site-packages\pyparsing.py", line 558, in parse
loc,tokens = self.parseImpl( instring, loc, doActions )
File "c:\python24\Lib\site-packages\pyparsing.py", line 1518, in parseImpl
return self.expr.parse( instring, loc, doActions )
File "c:\python24\Lib\site-packages\pyparsing.py", line 558, in parse
loc,tokens = self.parseImpl( instring, loc, doActions )
File "c:\python24\Lib\site-packages\pyparsing.py", line 1367, in parseImpl
loc, exprtokens = e.parse( instring, loc, doActions )
File "c:\python24\Lib\site-packages\pyparsing.py", line 558, in parse
loc,tokens = self.parseImpl( instring, loc, doActions )
File "c:\python24\Lib\site-packages\pyparsing.py", line 1518, in parseImpl
return self.expr.parse( instring, loc, doActions )
File "c:\python24\Lib\site-packages\pyparsing.py", line 560, in parse
raise ParseException, ( instring, len(instring), self.errmsg, self )
ParseException: Expected "}" (at char 9909), (line:325, col:5)
The offending code can be found here (includes the data) - http://www.rafb.net/paste/results/L560wx80.html
It's like pyparsing isn't recognising a lot of my "}"'s, as if I add another one, it throws the same error, same for adding another two...
No doubt I've done something silly, but any help in finding the tragic flaw would be much appreciated. I need to get a parsingResults object out so I can learn how to work with the basic structure!
Much regards,
Liam Clarke--On 7/21/05, Paul McGuire < [EMAIL PROTECTED]> wrote:Liam, Kent, and Danny -
It sure looks like pyparsing is taking on a life of its own! I can see I no
longer am the only one pitching pyparsing at some of these applications!
Yes, Liam, it is possible to create dictionary-like objects, that is,
ParseResults objects that have named values in them. I looked into your
application, and the nested assignments seem very similar to a ConfigParse
type of structure. Here is a pyparsing version that handles the test data
in your original post (I kept Danny Yoo's recursive list values, and added
recursive dictionary entries):
--------------------------
import pyparsing as pp
listValue = pp.Forward()
listSeq = pp.Suppress ('{') + pp.Group(pp.ZeroOrMore(listValue)) +
pp.Suppress('}')
listValue << ( pp.dblQuotedString.setParseAction(pp.removeQuotes) |
pp.Word(pp.alphanums) | listSeq )
keyName = pp.Word( pp.alphas )
entries = pp.Forward()
entrySeq = pp.Suppress('{') + pp.Group(pp.OneOrMore(entries)) +
pp.Suppress('}')
entries << pp.Dict(
pp.OneOrMore (
pp.Group( keyName + pp.Suppress('=') + (entrySeq |
listValue) ) ) )
--------------------------
Dict is one of the most confusing classes to use, and there are some
examples in the examples directory that comes with pyparsing (see
dictExample2.py), but it is still tricky. Here is some code to access your
input test data, repeated here for easy reference:
--------------------------
testdata = """\
country = {
tag = ENG
ai = {
flags = { }
combat = { DAU FRA ORL PRO }
continent = { }
area = { }
region = { "British Isles" "NorthSeaSea" "ECAtlanticSea" "NAtlanticSea"
"TagoSea" "WCAtlanticSea" }
war = 60
ferocity = no
}
}
"""
parsedEntries = entries.parseString(testdata)
def dumpEntries(dct,depth=0):
keys = dct.keys()
keys.sort()
for k in keys:
print (' '*depth) + '- ' + k + ':',
if isinstance(dct[k],pp.ParseResults):
if dct[k][0].keys():
dumpEntries(dct[k][0],depth+1)
else:
print dct[k][0]
else:
print dct[k]
dumpEntries( parsedEntries )
print parsedEntries.country[0].tag
print parsedEntries.country[0].ai[0].war
print parsedEntries.country[0].ai[0].ferocity
--------------------------
This will print out:
--------------------------
- country:
- ai:
- area: []
- combat: ['DAU', 'FRA', 'ORL', 'PRO']
- continent: []
- ferocity: no
- flags: []
- region: ['British Isles', 'NorthSeaSea', 'ECAtlanticSea',
'NAtlanticSea', 'TagoSea', 'WCAtlanticSea']
- war: 60
- tag: ENG
ENG
60
No
--------------------------
But I really dislike having to dereference those nested values using the
0'th element. So I'm going to fix pyparsing so that in the next release,
you'll be able to reference the sub-elements as:
print parsedEntries.country.tag
print parsedEntries.country.ai.war
print parsedEntries.country.ai.ferocity
This *may* break some existing code, but Dict is not heavily used, based on
feedback from users, and this may make it more useful in general, especially
when data parses into nested Dict's.
Hope this sheds more light than confusion!
-- Paul McGuire
_______________________________________________
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
'There is only one basic human right, and that is to do as you damn well please.
And with it comes the only basic human duty, to take the consequences.'
--
'There is only one basic human right, and that is to do as you damn well please.
And with it comes the only basic human duty, to take the consequences.'
_______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
