try: import bz2 except ImportError: bz2 = None try: import zlib except ImportError: zlib = None try: import cPickle as pickle except ImportError: import pickle from peewee import BlobField from peewee import buffer_type class CompressedField(BlobField): ZLIB = 'zlib' BZ2 = 'bz2' algorithm_to_import = { ZLIB: zlib, BZ2: bz2, } def __init__(self, compression_level=6, algorithm=ZLIB, *args, **kwargs): self.compression_level = compression_level if algorithm not in self.algorithm_to_import: raise ValueError('Unrecognized algorithm %s' % algorithm) compress_module = self.algorithm_to_import[algorithm] if compress_module is None: raise ValueError('Missing library required for %s.' % algorithm) self.algorithm = algorithm self.compress = compress_module.compress self.decompress = compress_module.decompress super(CompressedField, self).__init__(*args, **kwargs) def python_value(self, value): if value is not None: return self.decompress(value) def db_value(self, value): if value is not None: return self._constructor( self.compress(value, self.compression_level)) class PickleField(BlobField): def python_value(self, value): if value is not None: if isinstance(value, buffer_type): value = bytes(value) return pickle.loads(value) def db_value(self, value): if value is not None: pickled = pickle.dumps(value, pickle.HIGHEST_PROTOCOL) return self._constructor(pickled)