structure - Python ctypes.BigEndianStructure can't store a value -

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i in trouble ctypes.bigendianstructure. can't value set 1 fields. code this.

import ctypes class mystructure(ctypes.bigendianstructure):     _pack_ = 1     _fields_ = [         ('fx', ctypes.c_uint, 7),         ('fy', ctypes.c_ubyte, 1)     ]  x = mystructure()

it prints 0 excepted:

print x.fy  # prints 0

then set value still prints 0:

x.fy = 1 print x.fy  # still prints 0

i don't know why doing doesn't work , strange behavior. think alternative code works.

import ctypes class mystructure(ctypes.bigendianstructure):     _pack_ = 1     def __init__(self):         self.fx=ctypes.c_uint(7)         self.fy = ctypes.c_ubyte(1)  x = mystructure() x.fy = 7 print x.fy # prints 7

or without constructor::

import ctypes class mystructure(ctypes.bigendianstructure):     _pack_ = 1     fx = ctypes.c_uint(7)     fy = ctypes.c_ubyte(1)  x = mystructure() x.fy = 7 print x.fy # prints 7

i have never used fields attribute can't speak odd behavior.


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