Source code for langchain.retrievers.self_query.astradb

"""Logic for converting internal query language to a valid AstraDB query."""
from typing import Dict, Tuple, Union

from langchain_core.structured_query import (
    Comparator,
    Comparison,
    Operation,
    Operator,
    StructuredQuery,
    Visitor,
)

MULTIPLE_ARITY_COMPARATORS = [Comparator.IN, Comparator.NIN]


[docs]class AstraDBTranslator(Visitor): """Translate AstraDB internal query language elements to valid filters.""" """Subset of allowed logical comparators.""" allowed_comparators = [ Comparator.EQ, Comparator.NE, Comparator.GT, Comparator.GTE, Comparator.LT, Comparator.LTE, Comparator.IN, Comparator.NIN, ] """Subset of allowed logical operators.""" allowed_operators = [Operator.AND, Operator.OR] def _format_func(self, func: Union[Operator, Comparator]) -> str: self._validate_func(func) map_dict = { Operator.AND: "$and", Operator.OR: "$or", Comparator.EQ: "$eq", Comparator.NE: "$ne", Comparator.GTE: "$gte", Comparator.LTE: "$lte", Comparator.LT: "$lt", Comparator.GT: "$gt", Comparator.IN: "$in", Comparator.NIN: "$nin", } return map_dict[func]
[docs] def visit_operation(self, operation: Operation) -> Dict: args = [arg.accept(self) for arg in operation.arguments] return {self._format_func(operation.operator): args}
[docs] def visit_comparison(self, comparison: Comparison) -> Dict: if comparison.comparator in MULTIPLE_ARITY_COMPARATORS and not isinstance( comparison.value, list ): comparison.value = [comparison.value] comparator = self._format_func(comparison.comparator) return {comparison.attribute: {comparator: comparison.value}}
[docs] def visit_structured_query( self, structured_query: StructuredQuery ) -> Tuple[str, dict]: if structured_query.filter is None: kwargs = {} else: kwargs = {"filter": structured_query.filter.accept(self)} return structured_query.query, kwargs