Python pyparsing.replaceWith() Examples

def _wrap_as_optional_numeric(self, field, name, columns):
        # Regular expression accepting as many whitespaces as columns
        field_empty = pp.Regex('[0]{' + str(columns) + '}')

        resultsName = field.resultsName

        field_empty.setName(name)

        # Whitespaces are not removed
        field_empty.leaveWhitespace()

        # None is returned by this rule
        field_empty.setParseAction(pp.replaceWith(None))

        field_empty = field_empty.setResultsName(field.resultsName)

        field = field | field_empty

        field.setName(name)
        field = field.setResultsName(resultsName)

        field.leaveWhitespace()

        return field 

def _match_boolean(literal):
    return (
        literal
        + pyparsing.Empty().setParseAction(pyparsing.replaceWith("="))
        + pyparsing.Empty().setParseAction(pyparsing.replaceWith(True))
    ) 

def fixto(output, item):
    """Forces an item to result in a specific output."""
    return _coconut_tail_call(attach, replaceWith(output), item) 

def make_integer_word_expr(int_name, int_value):
    return pp.CaselessKeyword(int_name).addParseAction(pp.replaceWith(int_value)) 

def plural(s):
    return CK(s) | CK(s + "s").addParseAction(pp.replaceWith(s)) 

def makeLit(s, val):
    ret = pp.CaselessLiteral(s)
    return ret.setParseAction(pp.replaceWith(val)) 

def make_keyword(kwd_str, kwd_value):
    return pp.Keyword(kwd_str).setParseAction(pp.replaceWith(kwd_value)) 

def romanNumeralLiteral(numeralString, value):
    return pp.Literal(numeralString).setParseAction(pp.replaceWith(value)) 

def _wrap_as_optional(self, field, name, columns):
        """
        Adds a wrapper rule to the field to accept empty strings.

        This empty string should be of the same size as the columns parameter.
        One smaller or bigger will be rejected.

        This wrapper will return None if the field is empty.

        :param field: the field to wrap
        :param name: name of the field
        :param columns: number of columns it takes
        :return: the field with an additional rule to allow empty strings
        """
        # Regular expression accepting as many whitespaces as columns
        field_empty = pp.Regex('[ ]{' + str(columns) + '}')

        resultsName = field.resultsName

        field_empty.setName(name)

        # Whitespaces are not removed
        field_empty.leaveWhitespace()

        # None is returned by this rule
        field_empty.setParseAction(pp.replaceWith(None))

        field_empty = field_empty.setResultsName(resultsName)

        field = field | field_empty

        field.setName(name)
        field = field.setResultsName(resultsName)

        field.leaveWhitespace()

        return field 

def audio_visual_key(name=None):
    """
    Creates the grammar for an Audio Visual Key code.

    This is a variation on the ISAN (International Standard Audiovisual Number)

    :param name: name for the field
    :return: grammar for an ISRC field
    """

    if name is None:
        name = 'AVI Field'

    society_code = basic.numeric(3)
    society_code = society_code.setName('Society Code') \
        .setResultsName('society_code')

    av_number = basic.alphanum(15, extended=True, isLast=True)
    field_empty = pp.Regex('[ ]{15}')
    field_empty.setParseAction(pp.replaceWith(''))
    av_number = av_number | field_empty
    av_number = av_number.setName('Audio-Visual Number') \
        .setResultsName('av_number')

    field = pp.Group(society_code + pp.Optional(av_number))

    field.setParseAction(lambda v: _to_avi(v[0]))

    field = field.setName(name)

    return field.setResultsName('audio_visual_key') 

def jsParse(inStr):
	# This disaster is a context-free grammar parser for parsing javascript object literals.
	# It needs to be able to handle a lot of the definitional messes you find in in-the-wild
	# javascript object literals.
	# Unfortunately, Javascript is /way/ more tolerant then JSON when it comes to object literals
	# so we can't just parse objects using python's `json` library.

	TRUE = pp.Keyword("true").setParseAction( pp.replaceWith(True) )
	FALSE = pp.Keyword("false").setParseAction( pp.replaceWith(False) )
	NULL = pp.Keyword("null").setParseAction( pp.replaceWith(None) )

	jsonString = pp.quotedString.setParseAction( pp.removeQuotes )
	jsonNumber = pp.Combine( pp.Optional('-') + ( '0' | pp.Word('123456789',pp.nums) ) +
											pp.Optional( '.' + pp.Word(pp.nums) ) +
											pp.Optional( pp.Word('eE',exact=1) + pp.Word(pp.nums+'+-',pp.nums) ) )

	jsonObject   = pp.Forward()
	jsonValue    = pp.Forward()
	jsonDict     = pp.Forward()
	jsonArray    = pp.Forward()
	jsonElements = pp.Forward()

	rawText      = pp.Regex('[a-zA-Z_$][0-9a-zA-Z_$]*')

	commaToNull = pp.Word(',,', exact=1).setParseAction(pp.replaceWith(None))
	jsonElements << pp.ZeroOrMore(commaToNull) + pp.Optional(jsonObject) + pp.ZeroOrMore((pp.Suppress(',') + jsonObject) | commaToNull)

	jsonValue << ( jsonString | jsonNumber | TRUE | FALSE | NULL )


	dictMembers = pp.delimitedList( pp.Group( (rawText | jsonString) + pp.Suppress(':') + (jsonValue | jsonDict | jsonArray)))
	jsonDict << ( pp.Dict( pp.Suppress('{') + pp.Optional(dictMembers) + pp.ZeroOrMore(pp.Suppress(',')) + pp.Suppress('}') ) )
	jsonArray << ( pp.Group(pp.Suppress('[') + pp.Optional(jsonElements) + pp.Suppress(']') ) )
	jsonObject << (jsonValue | jsonDict | jsonArray)

	jsonComment = pp.cppStyleComment
	jsonObject.ignore( jsonComment )

	def convertDict(s, l, toks):

		return dict(toks.asList())

	def convertNumbers(s,l,toks):
		n = toks[0]
		try:
			return int(n)
		except ValueError:
			return float(n)

	jsonNumber.setParseAction(convertNumbers)
	jsonDict.setParseAction(convertDict)

	# jsonObject.setDebug()
	jsonObject.parseString('"inStr"').pop()
	return jsonObject.parseString(inStr).pop()


# Stolen from http://stackoverflow.com/a/12017573/268006