Metadata-Version: 2.1
Name: construct
Version: 2.10.70
Summary: A powerful declarative symmetric parser/builder for binary data
Home-page: http://construct.readthedocs.org
Author: Arkadiusz Bulski, Tomer Filiba, Corbin Simpson
Author-email: arek.bulski@gmail.com, tomerfiliba@gmail.com, MostAwesomeDude@gmail.com
License: MIT
Project-URL: Source, https://github.com/construct/construct
Project-URL: Documentation, https://construct.readthedocs.io/en/latest/
Project-URL: Issues, https://github.com/construct/construct/issues
Keywords: construct,kaitai,declarative,data structure,struct,binary,symmetric,parser,builder,parsing,building,pack,unpack,packer,unpacker
Platform: POSIX
Platform: Windows
Classifier: Development Status :: 5 - Production/Stable
Classifier: License :: OSI Approved :: MIT License
Classifier: Intended Audience :: Developers
Classifier: Topic :: Software Development :: Libraries :: Python Modules
Classifier: Topic :: Software Development :: Build Tools
Classifier: Topic :: Software Development :: Code Generators
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 :: 3.11
Classifier: Programming Language :: Python :: Implementation :: CPython
Classifier: Programming Language :: Python :: Implementation :: PyPy
Requires-Python: >=3.6
License-File: LICENSE
Provides-Extra: extras
Requires-Dist: arrow ; extra == 'extras'
Requires-Dist: cloudpickle ; extra == 'extras'
Requires-Dist: cryptography ; extra == 'extras'
Requires-Dist: lz4 ; extra == 'extras'
Requires-Dist: numpy ; extra == 'extras'
Requires-Dist: ruamel.yaml ; extra == 'extras'

Construct 2.10
===================

Construct is a powerful **declarative** and **symmetrical** parser and builder for binary data.

Instead of writing *imperative code* to parse a piece of data, you declaratively define a *data structure* that describes your data. As this data structure is not code, you can use it in one direction to *parse* data into Pythonic objects, and in the other direction, to *build* objects into binary data.

The library provides both simple, atomic constructs (such as integers of various sizes), as well as composite ones which allow you form hierarchical and sequential structures of increasing complexity. Construct features **bit and byte granularity**, easy debugging and testing, an **easy-to-extend subclass system**, and lots of primitive constructs to make your work easier:

* Fields: raw bytes or numerical types
* Structs and Sequences: combine simpler constructs into more complex ones
* Bitwise: splitting bytes into bit-grained fields
* Adapters: change how data is represented
* Arrays/Ranges: duplicate constructs
* Meta-constructs: use the context (history) to compute the size of data
* If/Switch: branch the computational path based on the context
* On-demand (lazy) parsing: read and parse only what you require
* Pointers: jump from here to there in the data stream
* Tunneling: prefix data with a byte count or compress it


Example
---------

A ``Struct`` is a collection of ordered, named fields::

    >>> format = Struct(
    ...     "signature" / Const(b"BMP"),
    ...     "width" / Int8ub,
    ...     "height" / Int8ub,
    ...     "pixels" / Array(this.width * this.height, Byte),
    ... )
    >>> format.build(dict(width=3,height=2,pixels=[7,8,9,11,12,13]))
    b'BMP\x03\x02\x07\x08\t\x0b\x0c\r'
    >>> format.parse(b'BMP\x03\x02\x07\x08\t\x0b\x0c\r')
    Container(signature=b'BMP')(width=3)(height=2)(pixels=[7, 8, 9, 11, 12, 13])

A ``Sequence`` is a collection of ordered fields, and differs from ``Array`` and ``GreedyRange`` in that those two are homogenous::

    >>> format = Sequence(PascalString(Byte, "utf8"), GreedyRange(Byte))
    >>> format.build([u"lalaland", [255,1,2]])
    b'\nlalaland\xff\x01\x02'
    >>> format.parse(b"\x004361789432197")
    ['', [52, 51, 54, 49, 55, 56, 57, 52, 51, 50, 49, 57, 55]]