Hi all:
Been working with pyparsing for a few days now and need some help with
the following
I have a file which is read on startup to either create or create and
populate classes
The following would be a valid input file
Class1::Instance1
Class1::Instance2
Class1::Instance3 {
variable1 = TRUE
variable2 = FALSE
variable3 = { {"valuename1", 10},
{"valuename2", 20} }
variable4 = { {10, "valuename3"} }
variable5 = "variable5value" }
Class1::Instance4
Class2::Instance1
etc, etc.
My parser looks as follows
def importFile_BNF():
global importBNF
# if importBNF: # We've been here before. Don't do it again
# return importBNF
# Literals not to be stored
LCB, RCB, COMMA, DQT = map(Suppress, '{},"')
DCLN = Suppress(Literal('::'))
comment = Suppress(Literal('#') + Optional(restOfLine))
assign = Suppress(Literal('='))
insert = Suppress(Literal('+='))
remove = Suppress(Literal ('-='))
operation = assign ^ insert ^ remove
classIdentifier = Word(alphas , alphanums + '_')
instanceIdentifier = Word(alphas, alphanums + '_-')
name = DQT + instanceIdentifier + DQT
order = Word(nums)
driverEntry = LCB + name + order + RCB
valueList = LCB + OneOrMore(driverEntry) + Optional(COMMA) + RCB
statement = instanceIdentifier + assign + valueList
identifier = Group(classIdentifier + DCLN + instanceIdentifier)
stanzaBody = LCB + OneOrMore(statement) + RCB
stanza = identifier + Optional(stanzaBody)
stanza.setDebug()
importBNF = ZeroOrMore(stanza)
importBNF.setDefaultWhitespaceChars(' \t\r')
importBNF.ignore(comment)
importBNF.ignore(blankline)
return importBNF
What happens when I run this is that when I reach the LCB on Class1::Instance3 I get an exception
that says "Expected W:(abcd.....) (at char XXX), (line:YY, col ZZ)
Having the stanza body marked optional should allow the opening LCB to be parsed, but it appears
that the parser is insisting that I only do 'definitions' and will not allow me to populate the class.
Any help is greatly appreciated.
Kevin
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