pyparsing

问题 I have a grammar token specified as: list_value = Suppress(oneOf("[ (")) + Group( delimitedList(string_value | int_value))("list") + Suppress(oneOf("] )")) However, this obviously allows (foo, bar] How do I enforce that the lists opening and closing characters must match? 回答1: You make a list a choice between two rules: one for parentheses and one for square brackets. Thanks for bringing up pyparsing. I like it. My answer for your question is: delim_value = Group(delimitedList(string_value |

问题 I am using pyparsing and am trying to use the method Skipto to reach the first occurence of several possible Literals in the text. Imagine something similar to this: OneOrMore(SkipTo(...longer expression...) | SkipTo(...another long expression...)) And I cannot fuse the two SkipTo's as they are located in different classes and it would not fit into the current system to fuse those classes. If I now have a text similar to this one: ...a lot of stuff... Example2 ...more stuff... Example1 ..

问题 My eventual goal is to apply sql-where-clause-style queries to filter pandas dataframes. Some searching led me to pyparsing's infixNotation method. I found an example of infix notation here: http://nullege.com/codes/show/src%40p%40y%40pyparsing-2.0.2%40examples%40simpleBool.py/15/pyparsing.infixNotation/python# but that actually processes the notation, and I need to use the tree multiple times on different data. Looking for help with parse trees I found this: http://pyparsing.wikispaces.com

问题 With pyparsing I need to write a matcher for expressions like a + names + c with a = pp.OneOrMore(pp.Word(pp.alphas)) c = pp.OneOrMore(pp.Word(pp.nums)) and names matching one of many entries in the string list names_list . The two complications are: The entries in names_list can contain spaces . The matching needs to be case-insensitive . names_list is rather large (~20000 entries) I tried names_kw_list = [pp.Keyword(name, caseless=True) for name in names_list ] names = pp.Or(names_kw_list)

问题 I'm trying to implement something in ply, which I'm very new to, based on what I have done in pyparsing, which I'm also quite new to. How can I write a simple nesting search such as this: thecontent = pyparsing.Word(pyparsing.alphanums) | '&' | '|' parens = pyparsing.nestedExpr( '(', ')', content=thecontent) By using PLY? 回答1: What you have written in pyparsing does not translate well to PLY because, well, it's barely even a parser. nestedExpr is a helper for quickly defining an expression of

问题 Here is the text I'm parsing: x ~ normal(mu, 1) y ~ normal(mu2, 1) The parser matches those lines using: model_definition = Group(identifier.setResultsName('random_variable_name') + '~' + expression).setResultsName('model_definition') // end of line: .setResultsName('model_definition') The problem is that when there are two model definitions, they aren't named separately in the ParseResults object: It looks like the first one gets overridden by the second. The reason I'm naming them is to

问题 I'm trying to parse some functions arguments with PyParsing but am having trouble getting the right syntax. Namely, given: str = "(key=val())" I would like the parser to return ['key', 'val()'] . I've been trying to get this to work with the following code; the .suppress() calls are intentionally omitted for clarity. ob = Literal("(") cb = Literal(")") key = Word(alphas) value = Word(alpha + "()") parser = ob + key + "=" + value + cb print parser.parseString(str) but of course it's matching

问题 I have a simple data set to parse with lines like the following: R1 (a/30) to R2 (b/30), metric 30 The only data that I need from the above is as follows: R1, a, 30, R2, 192.168.0.2, 30, 30 I can parse all of this easily with pyparsing, but I either end up with a bunch of literals in my output, or I have to specifically say Literal(thing).suppress() in my parsing grammar, which gets tiresome. Ideally, I'd like to write a grammar for the above like: Word(alphanums) + '(' + Word(alphanums) + '/

问题 I have defined these as part of my grammar in pyparsing argument = oneOf(valid_arguments) function_name = oneOf(valid_functions) function_call = Group(function_name + LPAR + argument + RPAR) where valid_argument and valid_function are lists of strings containing valid argument names and function names respectively. Now I want to generate custom exceptions in case if the column name is not part of valid_arguments and function_name is not one of the function names. How can I do that with

问题 I am trying to parse a partially standardized street address into it's components using pyparsing . I want to non-greedy match a street name that may be N tokens long. For example: 444 PARK GARDEN LN Should be parsed into: number: 444 street: PARK GARDEN suffix: LN How would I do this with PyParsing? Here's my initial code: from pyparsing import * def main(): street_number = Word(nums).setResultsName('street_number') street_suffix = oneOf("ST RD DR LN AVE WAY").setResultsName('street_suffix')