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Viewing changes to Lib/io/dumb_shelve.py

  • Committer: Bazaar Package Importer
  • Author(s): Daniel T. Chen (new)
  • Date: 2005-03-16 02:15:29 UTC
  • Revision ID: james.westby@ubuntu.com-20050316021529-xrjlowsejs0cijig
Tags: upstream-0.3.2
Import upstream version 0.3.2

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Lib/io/dumb_shelve.py
 
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from shelve import Shelf
 
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try:
 
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    import zlib
 
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except ImportError:
 
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    # Some python installations don't have zlib.
 
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    pass    
 
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from cStringIO import  StringIO
 
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import  cPickle  
 
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class DbfilenameShelf(Shelf):
 
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    """Shelf implementation using the "anydbm" generic dbm interface.
 
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    This is initialized with the filename for the dbm database.
 
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    See the module's __doc__ string for an overview of the interface.
 
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    """
 
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    def __init__(self, filename, flag='c'):
 
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        import dumbdbm_patched
 
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        Shelf.__init__(self, dumbdbm_patched.open(filename, flag))
 
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    def __getitem__(self, key):
 
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        compressed = self.dict[key]
 
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        try:
 
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            r = zlib.decompress(compressed)
 
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        except zlib.error:
 
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            r = compressed
 
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        except NameError:
 
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            r = compressed    
 
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        return cPickle.loads(r) 
 
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    def __setitem__(self, key, value):
 
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        s = cPickle.dumps(value,1)
 
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        try:
 
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            self.dict[key] = zlib.compress(s)
 
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        except NameError:
 
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            #zlib doesn't exist, leave it uncompressed.
 
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            self.dict[key] = s
 
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def open(filename, flag='c'):
 
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    """Open a persistent dictionary for reading and writing.
 
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    Argument is the filename for the dbm database.
 
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    See the module's __doc__ string for an overview of the interface.
 
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    """
 
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    return DbfilenameShelf(filename, flag)