class_docstr: Invokes a :class:`.BakedQuery` against a :class:`.Session`.
  
  The :class:`_baked.Result` object is where the actual :class:`.query.Query`
  object gets created, or retrieved from the cache,
  against a target :class:`.Session`, and is then invoked for results.
class_docstr_tok: ["Invokes","a",":","class",":","`",".BakedQuery","`","against","a",":","class",":","`",".Session","`",".","The",":","class",":","`","_baked.Result","`","object","is","where","the","actual",":","class",":","`",".query.Query","`","object","gets","created",",","or","retrieved","from","the","cache",",","against","a","target",":","class",":","`",".Session","`",",","and","is","then","invoked","for","results","."]
docstr: Return exactly one result or raise an exception.
  
  Equivalent to :meth:`_query.Query.one`.
docstr_tok: ["Return","exactly","one","result","or","raise","an","exception",".","Equivalent","to",":","meth",":","`","_query.Query.one","`","."]
code: def one(self):
      """Return exactly one result or raise an exception.
  
      Equivalent to :meth:`_query.Query.one`.
  
      """
      return self._iter().one()
  
imports: import collections.abc
  import logging
  from ..None import exc
  from ..None import util
  from ..orm import exc
  from ..orm.query import Query
  from ..orm.session import Session
  from ..sql import func
  from ..sql import literal_column
  from ..sql import util
label_desc: Use image node_id 12 for calling the Result obj's underlying member method code with example usage: obj.one() and returns: self