pyparsing Examples
This directory contains a number of Python scripts that can get you started in learning to use pyparsing.
- greeting.py
Parse "Hello, World!".
- greetingInKorean.py ~ submission by June Kim
Unicode example to parse "Hello, World!" in Korean.
- greetingInGreek.py ~ submission by ???
Unicode example to parse "Hello, World!" in Greek.
- holaMundo.py ~ submission by Marco Alfonso
"Hello, World!" example translated to Spanish, from Marco Alfonso's blog.
- chemicalFormulas.py
Simple example to demonstrate the use of ParseResults returned from parseString().
Parses a chemical formula (such as "H2O" or "C6H5OH"), and walks the returned list of tokens to calculate the molecular weight.
- wordsToNum.py
A sample program that reads a number in words (such as "fifteen hundred and sixty four"), and returns the actual number (1564).
Also demonstrates some processing of ParseExceptions, including marking where the parse failure was found.
- pythonGrammarparser.py ~ suggested by JH Stovall
A sample program that parses the EBNF used in the Python source code to define the Python grammar. From this parser,
one can generate Python grammar documentation tools, such as railroad track diagrams. Also demonstrates use of
Dict class.
- commasep.py
Demonstration of the use of the commaSeparatedList helper. Shows examples of
proper handling of commas within quotes, trimming of whitespace around delimited entries, and handling of consecutive commas (null arguments). Includes comparison with simple string.split(',').
- dictExample.py
A demonstration of using the Dict class, to parse a table of ASCII tabulated data.
- dictExample2.py ~ submission by Mike Kelly
An extended version of dictExample.py, in which Mike Kelly also parses the column headers, and generates a transposed version of the original table!
- scanExamples.py
Some examples of using scanString and transformString, as alternative parsing methods to parseString, to do macro substitution, and selection and/or removal of matching strings within a source file.
- urlExtractorNew.py
A sample program showing sample definitions and applications of HTML tag expressions
created using makeHTMLTags helper function. Very useful for scraping data from HTML pages.
- fourFn.py
A simple algebraic expression parser, that performs +,-,*,/, and ^ arithmetic operations. (With suggestions and bug-fixes graciously offered by Andrea Griffini.)
- SimpleCalc.py ~ submission by Steven Siew
An interactive version of fourFn.py, with support for variables.
- LAParser.py ~ submission by Mike Ellis
An interactive Linear Algebra Parser, an extension of SimpleCalc.py. Supports linear algebra (LA) notation for vectors, matrices, and scalars,
including matrix operations such as inversion and determinants. Converts LA expressions to C code - uses a separate C library for runtime
evaluation of results.
- configParse.py
A simple alternative to Python's ConfigParse module, demonstrating the use of the Dict class to return nested dictionary access to configuration values.
- getNTPserversNew.py
Yet another scanString example, to read/extract the list of NTP servers from NIST's web site.
Uses the new makeHTMLTags() method.
- httpServerLogParser.py
Parser for Apache server log files.
- idlParse.py
Parser for CORBA IDL files.
- mozillaCalendarParser.py
~ submission by Petri Savolainen
Parser for Mozilla calendar (*.ics) files.
- pgn.py ~ submission by Alberto Santini
Parser for PGN (Portable Game Notation) files, the standard form for documenting the moves in chess games.
- simpleSQL.py
A simple parser that will extract table and column names from SQL SELECT statements..
- dfmparse.py ~ submission by Dan Griffith
Parser for Delphi forms.
- ebnf.py / ebnftest.py ~ submission by Seo Sanghyeon
An EBNF-compiler that reads EBNF and generates a pyparsing grammar! Including a test that compiles... EBNF itself!
- searchparser.py ~ submission by Steven Mooij and Rudolph Froger
An expression parser that parses search strings, with special keyword and expression operations using (), not, and, or, and quoted strings.
- sparser.py ~ submission by Tim Cera
A configurable parser module that can be configured with a list of tuples, giving a high-level definition for parsing common sets
of water table data files. Tim had to contend with several different styles of data file formats, each with slight variations of its own.
Tim created a configurable parser (or "SPECIFIED parser" - hence the name "sparser"), that simply works from a config variable listing
the field names and data types, and implicitly, their order in the source data file.
See mayport_florida_8720220_data_def.txt for an
example configuration file.
- romanNumerals.py
A Roman numeral generator and parser example, showing the power of parse actions
to compile Roman numerals into their integer values.
- removeLineBreaks.py
A string transformer that converts text files with hard line-breaks into one with line breaks
only between paragraphs. Useful when converting downloads from
Project Gutenberg to import to word processing apps
that can reformat paragraphs once hard line-breaks are removed, or for loading into your Palm Pilot for portable perusal.
See Successful Methods of Public Speaking.txt and
Successful Methods of Public Speaking(2).txt for a sample
before and after (text file courtesy of Project Gutenberg).
- listAllMatches.py
An example program showing the utility of the listAllMatches option when specifying results naming.
- linenoExample.py
An example program showing how to use the string location to extract line and column numbers, or the
source line of text.
- parseListString.py
An example program showing a progression of steps, how to parse a string representation of a Python
list back into a true list.
- parsePythonValue.py
An extension of parseListString.py to parse tuples and dicts, including nested values,
returning a Python value of the original type.
- indentedGrammarExample.py
An example program showing how to parse a grammar using indentation for grouping,
such as is done in Python.
- simpleArith.py
An example program showing how to use the new operatorPrecedence helper method to define a 6-function
(+, -, *, /, ^, and !) arithmetic expression parser, with unary plus and minus signs.
- simpleBool.py
An example program showing how to use the new operatorPrecedence helper method to define a
boolean expression parser, with parse actions associated with each operator to "compile" the expression
into a data structure that will evaluate the expression's boolean value.
- simpleWiki.py
An example program showing how to use transformString to implement a simple Wiki markup parser.
- sql2dot.py~ submission by EnErGy [CSDX]
A nice graphing program that generates schema diagrams from SQL table definition statements.
- htmlStripper.py
An example implementation of a common application, removing HTML markup tags from an HTML page,
leaving just the text content.
- macroExpansion.py
An example implementation of a simple preprocessor, that will read embedded macro definitions
and replace macro references with the defined substitution string.
- sexpParser.py
A parser that uses a recursive grammar to parse S-expressions.
- nested.py
An example using nestedExpr, a helper method to simplify definitions of expressions of nested lists.
- withAttribute.py
An example using withAttribute, a helper method to define parse actions to validate matched HTML tags
using additional attributes. Especially helpful for matching common tags such as <DIV> and <TD>.
- stackish.py
A parser for the data representation format, Stackish.
- builtin_parse_action_demo.py
New in version 1.5.7
Demonstration of using builtins (min, max, sum, len, etc.) as parse actions.
- antlr_grammar.py~ submission by Luca DellOlio
New in version 1.5.7
Pyparsing example parsing ANTLR .a files and generating a working pyparsing parser.
- shapes.py
New in version 1.5.7
Parse actions example simple shape definition syntax, and returning the matched tokens as
domain objects instead of just strings.
- datetimeParseActions.py
New in version 1.5.7
Parse actions example showing a parse action returning a datetime object instead of
string tokens, and doing validation of the tokens, raising a ParseException if the
given YYYY/MM/DD string does not represent a valid date.
- position.py
New in version 1.5.7
Demonstration of a couple of different ways to capture the location a particular
expression was found within the overall input string.