pythontext-parsingpyparsingpeg

pyparsing: NotAny(FollowedBy()) failing

i have some input data like

[gog1] [G1] [gog2] [gog3] [gog4] [G2] [gog5] [G3] [gog6]

and want to find all gogs, if not G after it. so in this case i want to get gog2 and gog3 (and maybe gog6).

looks pretty simple, rigth? but i failed :(

import pyparsing as pp
from pyparsing import *

def pyparsing_test():
    # this also dont helps
    # ParserElement.enable_left_recursion(force=True)

    data=""" [gog1] [G1] [gog2] [gog3] [gog4] [G2] [gog5] [G3] [gog6] """

    poi_type = Word(alphas).set_results_name('type')
    poi = Suppress('[') + poi_type + Char(nums) + Suppress(']')

    def cnd_is_type(val):
        return lambda toks: toks.type==val

    def cnd_is_not_type(val):
        return lambda toks: toks.type!=val

    poi_gog=poi('gog').add_condition(cnd_is_type('gog'))
    poi_g=poi('g').add_condition(cnd_is_type('G'))
    poi_not_g=poi('not_g').add_condition(cnd_is_not_type('G'))

    pattern = poi_gog + ~poi_g
    #WTF this finds only `gog6`, why??

    pattern = poi_gog + NotAny(FollowedBy(poi_g))
    #WTF same, only `gog6`

    pattern = poi_gog + poi_not_g.suppress()
    #WTF this works better but find only `gog2`, why not `gog3` also?

    r=pattern.search_string(data)
    print(data)
    print('='*10)
    print(r)
Solution

  • Finnaly, we know whats happens, thanks to @ptmcg! His original answer on github https://github.com/pyparsing/pyparsing/issues/482#issuecomment-1546779260.

    Summary:

    First of all, need to use grouping with StringEnd() and this one works:

    pattern = poi_gog + FollowedBy(Group(poi_not_g) | StringEnd())

    About title problem - NotAny() have bug, it skips parse actions (and conditions). Current version pyparsing 3.0.9