[New-bugs-announce] [issue11241] ctypes: subclassing an already subclassed ArrayType generates AttributeError

[Steve Thompson]

New submission from Steve Thompson <steve.f.thompson at gmail.com>:

Consider the following:
python code:
class my_array( ctypes.Array ):
    _type_    = ctypes.c_uint8
    _length_  = 256

class my_array2( my_array ):
    pass

Output:
class my_array2( my_array ):
AttributeError: class must define a '_length_' attribute, which must be a positive integer


This is analogous to the C code
typedef char my_array[ 256 ];
typedef my_array my_array2;

However, the python code raises exceptions claiming _type_ and _length_ have not been defined.  This seems like a bug.  I shouldn't need to redefine _type_ and _length_, otherwise there was no point in subclassing my_array.

I tried to step into this using pdb but didn't have any luck.

----------
assignee: theller
components: ctypes
messages: 128769
nosy: Steve.Thompson, theller
priority: normal
severity: normal
status: open
title: ctypes: subclassing an already subclassed ArrayType generates AttributeError
type: behavior
versions: Python 2.6

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue11241>
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