`struct.unpack_from` doesn't work with `bytearray`?
binary-data, python
Solution
It looks like `buffer()` is the solution:
>>> struct.unpack_from('>h', buffer(bytearray('zabx')), 1)
(24930,)
`buffer()` is not a copy of the original, its a view:
>>> b0 = bytearray('xaby')
>>> b1 = buffer(b0)
>>> b1
<read-only buffer for ...>
>>> b1[1:3]
'ab'
>>> b0[1:3] = 'nu'
>>> b1[1:3]
'nu'
Alternitively, You(I?) can just use python 3; the limitation is lifted:
Python 3.2.3 (default, Jun 8 2012, 05:36:09)
[GCC 4.7.0 20120507 (Red Hat 4.7.0-5)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import struct
>>> struct.unpack_from('>h', b'xaby', 1)
(24930,)
>>> struct.unpack_from('>h', bytearray(b'xaby'), 1)
(24930,)
>>>
Problem
Unpacking from strings works: ``` >>> import struct >>> struct.unpack('>h', 'ab') (24930,) >>> struct.unpack_from('>h', 'zabx', 1) (24930,) ``` but if its a `bytearray`: ``` >>> struct.unpack_from('>h', bytearray('zabx'), 1) Traceback (most recent call last): File "<ipython-input-4-d58338aafb82>", line 1, in <module> struct.unpack_from('>h', bytearray('zabx'), 1) TypeError: unpack_from() argument 1 must be string or read-only buffer, not bytearray ``` Which seems a little odd. What am I actually supposed to do about it? obviously I could: ``` >>> struct.unpack_from('>h', str(bytearray('zabx')), 1) (24930,) ``` But i'm explicitly trying to avoid copying possibly large amounts of memory around.