| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293 |
- PyParsing -- A Python Parsing Module
- ====================================
- |Version| |Build Status| |Coverage| |License| |Python Versions| |Snyk Score|
- Introduction
- ============
- 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.
- *[Since first writing this description of pyparsing in late 2003, this
- technique for developing parsers has become more widespread, under the
- name Parsing Expression Grammars - PEGs. See more information on PEGs*
- `here <https://en.wikipedia.org/wiki/Parsing_expression_grammar>`__
- *.]*
- Here is a program to parse ``"Hello, World!"`` (or any greeting of the form
- ``"salutation, addressee!"``):
- .. code:: python
- from pyparsing import Word, alphas
- greet = Word(alphas) + "," + Word(alphas) + "!"
- hello = "Hello, World!"
- print(hello, "->", greet.parseString(hello))
- The program outputs the following::
- Hello, World! -> ['Hello', ',', 'World', '!']
- The Python representation of the grammar is quite readable, owing to the
- self-explanatory class names, and the use of '+', '|' and '^' operator
- definitions.
- The parsed results returned from ``parseString()`` is a collection of type
- ``ParseResults``, which can be accessed as a
- nested list, a dictionary, or an object with named attributes.
- The pyparsing module handles some of the problems that are typically
- vexing when writing text parsers:
- - extra or missing whitespace (the above program will also handle ``"Hello,World!"``, ``"Hello , World !"``, etc.)
- - quoted strings
- - embedded comments
- The examples directory includes a simple SQL parser, simple CORBA IDL
- parser, a config file parser, a chemical formula parser, and a four-
- function algebraic notation parser, among many others.
- Documentation
- =============
- There are many examples in the online docstrings of the classes
- and methods in pyparsing. You can find them compiled into `online docs <https://pyparsing-docs.readthedocs.io/en/latest/>`__. Additional
- documentation resources and project info are listed in the online
- `GitHub wiki <https://github.com/pyparsing/pyparsing/wiki>`__. An
- entire directory of examples can be found `here <https://github.com/pyparsing/pyparsing/tree/master/examples>`__.
- License
- =======
- MIT License. See header of the `pyparsing __init__.py <https://github.com/pyparsing/pyparsing/blob/master/pyparsing/__init__.py#L1-L23>`__ file.
- History
- =======
- See `CHANGES <https://github.com/pyparsing/pyparsing/blob/master/CHANGES>`__ file.
- .. |Build Status| image:: https://github.com/pyparsing/pyparsing/actions/workflows/ci.yml/badge.svg
- :target: https://github.com/pyparsing/pyparsing/actions/workflows/ci.yml
- .. |Coverage| image:: https://codecov.io/gh/pyparsing/pyparsing/branch/master/graph/badge.svg
- :target: https://codecov.io/gh/pyparsing/pyparsing
- .. |Version| image:: https://img.shields.io/pypi/v/pyparsing?style=flat-square
- :target: https://pypi.org/project/pyparsing/
- :alt: Version
- .. |License| image:: https://img.shields.io/pypi/l/pyparsing.svg?style=flat-square
- :target: https://pypi.org/project/pyparsing/
- :alt: License
- .. |Python Versions| image:: https://img.shields.io/pypi/pyversions/pyparsing.svg?style=flat-square
- :target: https://pypi.org/project/python-liquid/
- :alt: Python versions
- .. |Snyk Score| image:: https://snyk.io//advisor/python/pyparsing/badge.svg
- :target: https://snyk.io//advisor/python/pyparsing
- :alt: pyparsing
|
