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Questions tagged [pyparsing]

The pyparsing module is an alternative approach to creating and executing simple grammars, vs. the traditional lex/yacc approach, or the use of regular expressions. The pyparsing module provides a library of classes that client code uses to construct the grammar directly in Python code.

Pyparsing is a Python module for creating and executing simple grammars. This is an alternative approach to the traditional lex/yacc or regular expressions. The pyparsing module provides a library of classes that client code uses to construct the grammar directly in Python code.

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Split string at commas except when in bracket environment

I would like to split a Python multiline string at its commas, except when the commas are inside a bracketed expression. E.g., the string {J. Doe, R. Starr}, {Lorem {i}psum dolor }, Dol. sit., am. et. Should be split into ['{J. Doe, R. Starr}',…
Nico Schlömer
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Improving error messages with pyparsing

Edit: I did a first version, which Eike helped me to advance quite a bit on it. I'm now stuck to a more specific problem, which I will describe bellow. You can have a look at the original question in the history I'm using pyparsing to parse a small…
Jonathan Ballet
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How do I parse indents and dedents with pyparsing?

Here is a subset of the Python grammar: single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE stmt: simple_stmt | compound_stmt simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE small_stmt: pass_stmt pass_stmt: 'pass' compound_stmt:…
Markus Jarderot
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pyparsing - load ABNF?

can pyparsing read ABNF from a file instead of having to define it in terms of python objects? If not, is there something which can do similar (load an ABNF file into a parser object)
OJW
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pyparsing capturing groups of arbitrary text with given headers as nested lists

I have a text file that looks similar to; section header 1: some words can be anything more words could be anything at all etc etc lala some other header: as before could be anything hey isnt this fun I am trying to contruct a grammar…
Matt Warren
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pyparsing example

It is my first attempt to use pyparsing and I'd like to ask how to filter this sample line: survey = '''GPS,PN1,LA52.125133215643,LN21.031048525561,EL116.898812''' to get output like: 1,52.125133215643,21.031048525561,116.898812 In general I have…
daikini
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pyparsing performance and memory usage

Pyparsing worked fine for a very small grammar, but as the grammar has grown, the performance went down and the memory usage through the roof. My current gramar is: newline = LineEnd () minus = Literal ('-') plus = Literal ('+') star = Literal…
Hyperboreus
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pyparsing and line breaks

I just started with pyparsing and I have problems with line breaks. My grammar is: from pyparsing import * newline = LineEnd () #Literal ('\n').leaveWhitespace () minus = Literal ('-') plus = Literal ('+') lparen = Literal ('(') rparen = Literal…
Hyperboreus
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Simple demonstration of using pyparsing's indentedBlock recursively

I am trying to use indentedBlock in pyparsing (which looks awesome to me) to dissect some nested indentations, but am struggling a bit with comprehending its description in the API reference (or the more specific examples under…
texb
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Extending the matplotlib mathtext parser

For most of my interactive plotting with matplotlib, I don't want to use latex processing of math. (Mostly because it's too slow, but also because it's just that little bit too blurry for frequent use IMHO.) But I also use my own macros all the…
Mike
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pyparsing, forward, and recursion

I'm using pyparsing to parse vcd (value change dump) files. Essentially, I want to read in the files, parse it into an internal dictionary, and manipulate the values. Without going into details on the structure, my problem occurs with identifying…
RaytheonLiszt
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Convert BNF grammar to pyparsing

How can I describe a grammar using regex (or pyparsing is better?) for a script languge presented below (Backus–Naur Form): := | := [* ] := "{" "}" | ; :=…
Max Tkachenko
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Python delimited line split problems

I'm struggling to split text rows, based on variable delimiter, and preserve empty fields and quoted data. Examples: 1,"2",three,'four, 4',,"6\tsix" or as tab-delimited vesion 1\t"2"\tthree\t'four, 4'\t\t"6\tsix" Should both result in: ['1',…
user2123203
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How to disallow spaces in between literals in pyparsing?

grammar = Literal("from") + Literal(":") + Word(alphas) The grammar needs to reject from : mary and only accept from:mary i.e. without any interleaving spaces. How can I enforce this in pyparsing ? Thanks
Frankie Ribery
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Pyparsing: space as a valid token

I'm using pyparser to process the output of a hex-to-text converter. It prints out 16 characters per line, separated by spaces. If the hex value is an ASCII-printable character, that character is printed, otherwise the converter outputs a period…
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