NamedStruct, a combinationof struct and namedtuple in python, make code more readable

named_struct.py

"""
NamedStruct, a combinationof struct and namedtuple in python, make code more readable.
You can access the fields by name rather than index.
"""

from __future__ import print_function

import struct
from collections import namedtuple

_BYTE_ORDERS = (
    'native', 'little-endian', 'big-endian', 'network')


_TYPES = {
    'char' : 'c',
    'int8' : 'b',
    'uint8' : 'B',
    'bool' : '?',
    'int16' : 'h',
    'uint16' : 'H',
    'int32' : 'i',
    'uint32' : 'I',
    'int64' : 'q',
    'uint64' : 'Q',
    'float' : 'f',
    'double' : 'd',
    'string' : 's',
    'psacal_string' : 'p',
    'pointer' : 'P',
}

class NamedStruct(object):
    def __init__(self, name, fields, byteorder=''):
        self.name = name
        self.byteorder = byteorder
        self.fields, self.names, self.format = self._parse(fields)
        self._struct = struct.Struct(self.format)
        self._namedtuple = namedtuple(self.name, self.names)

    def sizeof(self):
        return self._struct.size()

    def pack(self, *args):
        return self._struct.pack(*args)

    def pack_into(self, buffer, offset, *args):
        return self._struct.pack_into(buffer, offset, *args)

    def unpack(self, string):
        return self._namedtuple._make(self._struct.unpack(string))

    def unpack_from(self, buffer, offset=0):
        return self._namedtuple._make(self._struct.unpack_from(buffer, offset))

    def __str__(self):
        return 'struct %s {\n  %s;\n}' % (self.name, ';\n  '.join(self.fields))

    def _string_type_format(self, type):
        type = type[len('string'):]
        return type[1:-1] + _TYPES['string']

    def _parse(self, fields):
        if isinstance(fields, str):
            fields = [f.strip() for f in fields.split(';')]
        format = self.byteorder
        names = []
        for f in fields:
            type, name = f.split()
            if type.startswith('string'):
                format += self._string_type_format(type)
            else:
                format += _TYPES[type]
            names.append(name)
        return fields, names, format


def main():
    record = 'raymond   \x32\x12\x08\x01\x08'
    Student = NamedStruct(
        'Student', [
            'string<10> name',
            'uint16 serialnumn',
            'uint16 school',
            'int8 gradelevel'],
        byteorder='<')
    print(Student)
    student = Student.unpack(record)
    print(student)


if __name__ == '__main__':
    main()

NamedStruct 让你可以用名字而不是下标来访问结构体成员，提高代码的可读性。

Origin from:
https://stackoverflow.com/questions/11461125/is-there-an-elegant-way-to-use-struct-and-namedtuple-instead-of-this