pyparsing

Boštjan Jerko bostjan.jerko at mf.uni-lj.si
Thu May 13 02:05:32 EDT 2004


Hello !

I am trying to understand pyparsing. Here is a little test program 
to check Optional subclass:

from pyparsing import Word,nums,Literal,Optional

lbrack=Literal("[").suppress()
rbrack=Literal("]").suppress()
ddot=Literal(":").suppress()
start = Word(nums+".")
step = Word(nums+".")
end = Word(nums+".")
        
sequence=lbrack+start+Optional(ddot+step)+ddot+end+rbrack

tokens = sequence.parseString("[0:0.1:1]")
print tokens

tokens1 = sequence.parseString("[1:2]")
print tokens1

It works on tokens, but the error message is showed on 
the second string ("[1:2]"). I don't get it. I did use 
Optional for ddot and step so I guess they are optional.

Any hints what I am doing wrong?

The versions are pyparsing 1.1.2 and Python 2.3.3.

Thanks,

B.



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