1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
Metadata-Version: 2.1
Name: pyparsing
Version: 3.0.9
Summary: pyparsing module - Classes and methods to define and execute parsing grammars
Author-email: Paul McGuire <ptmcg.gm+pyparsing@gmail.com>
Requires-Python: >=3.6.8
Description-Content-Type: text/x-rst
Classifier: Development Status :: 5 - Production/Stable
Classifier: Intended Audience :: Developers
Classifier: Intended Audience :: Information Technology
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Classifier: Programming Language :: Python :: 3.9
Classifier: Programming Language :: Python :: 3.10
Classifier: Programming Language :: Python :: 3 :: Only
Classifier: Programming Language :: Python :: Implementation :: CPython
Classifier: Programming Language :: Python :: Implementation :: PyPy
Classifier: Typing :: Typed
Requires-Dist: railroad-diagrams ; extra == "diagrams"
Requires-Dist: jinja2 ; extra == "diagrams"
Project-URL: Homepage, https://github.com/pyparsing/pyparsing/
Provides-Extra: diagrams
PyParsing -- A Python Parsing Module
====================================
|Build Status| |Coverage|
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.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
|
