Hi John,
Maybe you encountered the below issue in your Python programming, and you may
offer advise ?
I need to copy an instance of a class, where one of the items in the original
is a cStringIO.StringO object.
I do not need the cStringIO.StringO in the target object.
The target instance is to be pickled.
Googling made me devise the following plan: do a copy/deepcopy from the
original to the target, and then delete the cStringIO.StringO object from the
target.
However, trying to use copy.deepcopy produced (see full traceback below my
signature): TypeError: object.__new__(cStringIO.StringO) is not safe, use
cStringIO.StringO.__new__()
Is there a way to create a copy of the instance, sans the cStringIO.StringO ?
If I find no elegant way to do that, I thought of creating a "blank" target
instance; then iterating over the __dict__ of the original, and manually copy
the items to the target (while not copying the cStringIO.StringO to the target).
Trying that, I did:
for_pickle_log_stream = LogStream(sac_log_file)
for key in log_stream.__dict__:
if key != "input_file":
for_pickle_log_stream[key] = log_stream[key]
But that gave me:
Traceback (most recent call last):
File "c:\Documents and
Settings\rbarak\rbarak_devel\LogManager\./failover_pickle_demo02.py", line 393,
in <module>
for_pickle_log_stream[key] = log_stream[key]
AttributeError: FailoverMatches instance has no attribute '__getitem__'
Can you suggest a better way ?
Another question: Do you have an example of creating a __getitem__ method for
my class?
The class includes the following:
log_stream.__dict__:
{ 'db': [ { 'DPM': 'iSW-00-090',
'end_time': '2009 Dec 15 16:17:24',
'event': 'Volume failover',
'event_duration': 0L,
'first_line_pos': 12453,
'last_line_pos': 12871,
'rec_num': 0,
'start_time': '2009 Dec 15 16:17:24',
'volume_name': 'Domain 5:DVol1_1'},
{ 'DPM': 'iSW-00-090',
'end_time': '2009 Dec 15 16:17:24',
'event': 'Volume failover',
'event_duration': 0L,
'first_line_pos': 13409,
'last_line_pos': 13827,
'rec_num': 1,
'start_time': '2009 Dec 15 16:17:24',
'volume_name': 'Domain 5:DVol1_2'}],
'end_timestamp': 1260886645L,
'file_pointer': 58180,
'filename_array': [ u'C:\\Documents and
Settings\\rbarak\\rbarak_devel\\LogManager\\logs_3_vol\\sac.log.367lines.gz'],
'input_file': <cStringIO.StringO object at 0x01B3D700>,
'last_line_offset': 58181,
'log_stream_array': [<LogStream.LogStream instance at 0x01B87350>]}
(the red item is not needed in the target object).
Thanks,
Ron.
Traceback (most recent call last):
File "c:\Documents and
Settings\rbarak\rbarak_devel\LogManager\./failover_pickle_demo02.py", line 388,
in <module>
for_pickle_log_stream = copy.deepcopy(log_stream)
File "c:\Python25\lib\copy.py", line 162, in deepcopy
y = copier(x, memo)
File "c:\Python25\lib\copy.py", line 291, in _deepcopy_inst
state = deepcopy(state, memo)
File "c:\Python25\lib\copy.py", line 162, in deepcopy
y = copier(x, memo)
File "c:\Python25\lib\copy.py", line 254, in _deepcopy_dict
y[deepcopy(key, memo)] = deepcopy(value, memo)
File "c:\Python25\lib\copy.py", line 189, in deepcopy
y = _reconstruct(x, rv, 1, memo)
File "c:\Python25\lib\copy.py", line 322, in _reconstruct
y = callable(*args)
File "c:\Python25\lib\copy_reg.py", line 92, in __newobj__
return cls.__new__(cls, *args)
TypeError: object.__new__(cStringIO.StringO) is not safe, use
cStringIO.StringO.__new__()
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