pickle unable to load collection

[paragk]

On May 18, 12:10 am, Peter Otten <__pete... at web.de> wrote:
> paragk wrote:
> > Hi,
>
> > I am unable to figure out the cause of python pickle unable to find
> > the collection module.
>
> > I am getting
>
> >     __import__(module)
> > ImportError: No module named collections
>
> > when I try to load a pickled object.
>
> > Details:
>
> > Python version:
>
> > Python 2.6 (r26:66721, Oct  2 2008, 11:35:03) [MSC v.1500 32 bit
> > (Intel)] on win32
>
> > [CODE]
>
> > import sys
> > import glob
> > import collections
> > import pickle
>
> > ...
>
> > SomeListDict = collections.defaultdict(list)
>
> > ... # Populate SomeListDict
>
> > DictFile = open (options.saveDict, 'w')
> > pickle.dump(SomeListDict , DictFile, -1)
> > DictFile.close()
>
> [...]
>
> > From the above analysis, clearly the collection module exists, since
> > the dump works.
>
> > What am I missing?
>
> You have to open the file in binary mode "wb".
>
> >>> import collections
> >>> import pickle
> >>> data = pickle.dumps(collections.defaultdict())
> >>> pickle.loads(data)
>
> defaultdict(None, {})
>
> Now simulate the effect of writing in text mode and reading in binary mode:
>
> >>> garbled_data = data.replace("\n", "\r\n")
> >>> pickle.loads(garbled_data)
>
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "/usr/lib/python2.6/pickle.py", line 1374, in loads
>     return Unpickler(file).load()
>   File "/usr/lib/python2.6/pickle.py", line 858, in load
>     dispatch[key](self)
>   File "/usr/lib/python2.6/pickle.py", line 1090, in load_global
>     klass = self.find_class(module, name)
>   File "/usr/lib/python2.6/pickle.py", line 1124, in find_class
>     __import__(module)
> ImportError: No module named collections
>
> >>> try: pickle.loads(garbled_data)
>
> ... except ImportError as e:
> ...     e
> ...
> ImportError('No module named collections\r',)
>
> So as Steven suspected there was a whitespace char in the module name:
> pickle.load() was looking for the "collections\r" module.
>
> Peter

Thank you for the suggestions. Opening the file in 'wb' mode worked.

Thanks,
Parag