[Pyparsing] parsing issue

[mammar <ma...@gm...>]

Hi All,


I am a newbie to parsing and pyparsing. Here is my problem


input string could be one of the following:


   - an integer number(could be negative)
   - an integer number(could be negative) and STR1 and STR2


whereas STR1 is a single word(alphas only)
whereas STR2 is a string of alphas with spaces in between words


i wrote the following pyparsing code but both print statements are printing
-1 only, what is wrong?

A general question related to parsing and pyparsing, what should be the
output if
1. pattern matched
2. pattern not matched


from pyparsing import *

#exmple input strings
str1 = "-1"
str2 = "-1 ENOENT (No such file or directory)"

neg = Word("-", exact=1)

returnCodeNum = Combine(neg + Word(nums))

returnCodeSymbol = Word(alphas)

returnInfo = OneOrMore(Word(alphas))

returnCodeInfo = Combine("(" + returnInfo + ")")

rv2 = Combine( returnCodeNum + returnCodeSymbol + returnCodeInfo )

rv  = returnCodeNum | rv2


print rv.parseString(str1)
print rv.parseString(str2)