datastructclass

A DataStructClass is a dataclass with struct-like semantics. It can be serialized/deserialized to/from bytes.

A subclass of DataStructClass is a dataclass, with the following additional features:

<class>.format
<class>.size
<class>.unpack
<instance>.pack
<instance.__bytes__>

Each member of a DataStructClass must provide struct metadata via typing.Annotated.

Example

from struct import Struct
from typing import Annotated
from datastructclass import DataStructClass

class MyDSC(DataStructClass):
    # Unsigned long:
    member_a: Annotated[int, Struct("=L")]
    # Double:
    member_b: Annotated[float, Struct("=d")]
    # Array of signed long with length 4.
    member_c: Annotated[list[int], Struct("=4I")]
    # Array of char, aka. a string, with length 8:
    member_d: Annotated[bytes, Struct("=8s")]


data = MyDSC(4000, 3.14, [-2, -1, 0, 1], b"charlie  ")
# 'send_over_wire' could a network socket, a serial port, etc.
send_over_wire(data.pack())

Limitations

DataStructClass cannot contain variable-length members.