dict_destructure.py

#SUPPORTS# <= 3.9

import sys
import fishhook
import f_locals
import dis
from ctypes import c_byte

@fishhook.hook(dict)
def __iter__(self):
    frame = sys._getframe(1)
    ino = frame.f_lasti
    code = frame.f_code
    op = code.co_code[ino]
    arg = code.co_code[ino + 1]
    get_name = lambda op, arg:[
        code.co_names,
        code.co_varnames
    ][op == dis.opmap['STORE_FAST']][arg]
    copy = self.copy()
    ex = dis.opname[op] == 'UNPACK_EX'
    if dis.opname[op] in ('UNPACK_SEQUENCE', 'UNPACK_EX'):
        counts = arg, 0
    elif dis.opname[op] == 'EXTENDED_ARG' and \
         dis.opname[code.co_code[ino + 2]] == 'UNPACK_EX':
        ex = True
        ino += 2
        counts = code.co_code[ino + 1], arg
    else:
        yield from fishhook.orig(self)
        return
    exino = 0
    for num in counts:
        ino += 2
        while num:
            yield copy.pop(get_name(*code.co_code[ino: ino + 2]))
            ino += 2
            num -= 1
        if ex:
            exino = ino
            ex = False
    if exino:
        op, arg = code.co_code[exino: exino + 2]
        op_name = dis.opname[op]
        ex_name = get_name(op, arg)
        if op_name in ['STORE_GLOBAL', 'STORE_NAME']:
            frame.f_globals[ex_name] = copy
        elif op_name == 'STORE_FAST':
            frame.f_locals[ex_name] = copy
        address = id(code.co_code) + bytes.__basicsize__ - 1 + exino
        c_byte.from_address(address).value = dis.opmap['POP_TOP']
        def tfunc(*args):
            if getattr(tfunc, 'flag', False):
                c_byte.from_address(address).value = op
                sys.settrace(None)
            else:
                tfunc.flag = True
                return tfunc
        sys.settrace(tfunc)