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Description:

constructclasses 0.1.2

Parse your binary data into dataclasses. Pack your dataclasses into binary data.
construct-classes rely on construct for parsing and packing. The
programmer needs to manually write the Construct expressions. There is also no type
verification, so it is the programmer’s responsibility that the dataclass and the
Construct expression match.
For fully type annotated experience, install construct-typing.
This package typechecks with mypy and pyright.

Usage
Any child of Struct is a Python dataclass. It expects a Construct Struct
expression in the SUBCON attribute. The names of the attributes of the dataclass
must match the names of the fields in the Construct struct.
import construct as c
from construct_classes import Struct, subcon

class BasicStruct(Struct):
x: int
y: int
description: str

SUBCON = c.Struct(
"x" / c.Int32ul,
"y" / c.Int32ul,
"description" / c.PascalString(c.Int8ul, "utf8"),
)

data = b"\x01\x00\x00\x00\x02\x00\x00\x00\x05hello"
parsed = BasicStruct.parse(data)
print(parsed) # BasicStruct(x=1, y=2, description='hello')

new_data = BasicStruct(x=100, y=200, description="world")
print(new_data.build()) # b'\x64\x00\x00\x00\xc8\x00\x00\x00\x05world'
construct-classes support nested structs, but you need to declare them explicitly:
class LargerStruct(Struct):
# specify the subclass type:
basic: BasicStruct = subcon(BasicStruct)
# in case of a list, specify the item type:
basic_array: List[BasicStruct] = subcon(BasicStruct)
# the `subcon()` function supports all arguments of `dataclass.field`:
default_array: List[BasicStruct] = subcon(BasicStruct, default_factory=list)

# to refer to the subcon, use the `SUBCON` class attribute:
SUBCON = c.Struct(
"basic" / BasicStruct.SUBCON,
"basic_array" / c.Array(2, BasicStruct.SUBCON),
"default_array" / c.PrefixedArray(c.Int8ul, BasicStruct.SUBCON),
)
Use dataclasses.field() to specify attributes on fields that are not subcons.
There are currently no other features. In particular, the resulting class is a Python
dataclass, but you cannot specify its parameters like frozen etc.

Installing
Install using pip:

$ pip install construct-classes

Changelog
See CHANGELOG.rst.

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Free software: MIT License