Pyparsing help

Arnaud Delobelle arnodel at googlemail.com
Sun Mar 23 08:56:54 CET 2008


On Mar 22, 9:11 pm, rh0dium <steven.kl... at gmail.com> wrote:
> Hi all,

Hi,

> I am struggling with parsing the following data:
>
> test1 = """
> Technology      {
>                 name                            = "gtc"
>                 dielectric                      = 2.75e-05
[...]

I know it's cheating, but the grammar of your example is actually
quite simple and the values are valid python expressions, so here is a
solution without pyparsing (or regexps, for that matter).  *WARNING*
it uses the exec statement.

from textwrap import dedent

def parse(txt):
    globs, parsed = {}, {}
    units = txt.strip().split('}')[:-1]
    for unit in units:
        label, params = unit.split('{')
        paramdict = {}
        exec dedent(params) in globs, paramdict
        try:
            label, key = label.split()
            parsed.setdefault(label, {})[eval(key)] = paramdict
        except ValueError:
            parsed[label.strip()] = paramdict
    return parsed

>>> p = parse(test1)
>>> p['Layer']['PRBOUNDARY']
{'maskName': '', 'defaultWidth': 0, 'color': 'cyan', 'pattern':
'blank', 'layerNumber': 0, 'minSpacing': 0, 'blink': 0, 'minWidth': 0,
'visible': 1, 'pitch': 0, 'selectable': 1, 'lineStyle': 'solid'}
>>> p['Layer']['METAL2']['maskName']
'metal2'
>>> p['Technology']['gridResolution']
5
>>>

HTH

--
Arnaud




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