Re: [Pyparsing] Word and Regex matching more than they should
Brought to you by:
ptmcg
Menu
▾
▴
Re: [Pyparsing] Word and Regex matching more than they should
|
From: Stuart L. <st...@vr...> - 2018-01-22 05:28:47
|
On 22/01/18 10:06, Stuart Longland wrote:
> Okay, something is *definitely* buggy:
>> stuartl@vk4msl-ws ~/vrt/projects/widesky/sdk/hszinc $ ipython2
>> Python 2.7.14 (default, Jan 17 2018, 17:36:45)
>> Type "copyright", "credits" or "license" for more information.
>>
>> IPython 5.4.1 -- An enhanced Interactive Python.
>> ? -> Introduction and overview of IPython's features.
>> %quickref -> Quick reference.
>> help -> Python's own help system.
>> object? -> Details about 'object', use 'object??' for extra details.
>>
>> In [1]: import pyparsing as pp
>>
>> In [2]: class Quantity(object):
>> ...: def __init__(self, value, unit):
>> ...: self.value = value
>> ...: self.unit = unit
>> ...: def __repr__(self):
>> ...: return 'Q(%r, %r)' % (self.value, self.unit)
>> ...:
>>
>> In [3]: hs_unit = pp.Regex(ur"[a-zA-Z%_/$\x80-\xffffffff]+")
>> ...: hs_decimal = pp.Regex(r"-?[\d_]+(\.[\d_]+)?([eE][+\-]?[\d_]+)?").setParseAction(
>> ...: lambda toks : [float(toks[0].replace('_',''))])
>> ...: hs_quantity = (hs_decimal + hs_unit).setParseAction(
>> ...: lambda toks : [Quantity(toks[0], unit=toks[1])])
>> ...:
>>
>> In [4]: hs_quantity.parseString('123.123 abc')
>> Out[4]: ([Q(123.123, 'abc')], {})
>>
>> In [5]: hs_quantity.parseString('123.123 abc', parseAll=True)
>> Out[5]: ([Q(123.123, 'abc')], {})
> *Nowhere*, in those patterns, is a space allowed. Yet, it passes it
> through.
Okay, so the magic was `leaveWhitespace`… without that, it'll silently
discard whitespace in around tokens in the parser. Working around it is
a tad ugly, but doable:
https://github.com/vrtsystems/hszinc/commit/4b517d679dc40766340eba87660a7bdf858a68fc
Regards,
--
_ ___ Stuart Longland - Systems Engineer
\ /|_) | T: +61 7 3535 9619
\/ | \ | 38b Douglas Street F: +61 7 3535 9699
SYSTEMS Milton QLD 4064 http://www.vrt.com.au
|
