27 lines
722 B
Python
27 lines
722 B
Python
from sqlalchemy.dialects.postgresql.base import ischema_names
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from sqlalchemy.types import UserDefinedType, Float
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class BIT(UserDefinedType):
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cache_ok = True
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def __init__(self, length=None):
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super(UserDefinedType, self).__init__()
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self.length = length
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def get_col_spec(self, **kw):
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if self.length is None:
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return 'BIT'
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return 'BIT(%d)' % self.length
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class comparator_factory(UserDefinedType.Comparator):
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def hamming_distance(self, other):
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return self.op('<~>', return_type=Float)(other)
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def jaccard_distance(self, other):
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return self.op('<%>', return_type=Float)(other)
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# for reflection
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ischema_names['bit'] = BIT
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