Source code for langchain.retrievers.self_query.deeplake

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

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

COMPARATOR_TO_TQL = {
    Comparator.EQ: "==",
    Comparator.GT: ">",
    Comparator.GTE: ">=",
    Comparator.LT: "<",
    Comparator.LTE: "<=",
}


OPERATOR_TO_TQL = {
    Operator.AND: "and",
    Operator.OR: "or",
    Operator.NOT: "NOT",
}


[docs]def can_cast_to_float(string: str) -> bool: """Check if a string can be cast to a float.""" try: float(string) return True except ValueError: return False
[docs]class DeepLakeTranslator(Visitor): """Translate `DeepLake` internal query language elements to valid filters.""" allowed_operators = [Operator.AND, Operator.OR, Operator.NOT] """Subset of allowed logical operators.""" allowed_comparators = [ Comparator.EQ, Comparator.GT, Comparator.GTE, Comparator.LT, Comparator.LTE, ] """Subset of allowed logical comparators.""" def _format_func(self, func: Union[Operator, Comparator]) -> str: self._validate_func(func) if isinstance(func, Operator): value = OPERATOR_TO_TQL[func.value] # type: ignore elif isinstance(func, Comparator): value = COMPARATOR_TO_TQL[func.value] # type: ignore return f"{value}"
[docs] def visit_operation(self, operation: Operation) -> str: args = [arg.accept(self) for arg in operation.arguments] operator = self._format_func(operation.operator) return "(" + (" " + operator + " ").join(args) + ")"
[docs] def visit_comparison(self, comparison: Comparison) -> str: comparator = self._format_func(comparison.comparator) values = comparison.value if isinstance(values, list): tql = [] for value in values: comparison.value = value tql.append(self.visit_comparison(comparison)) return "(" + (" or ").join(tql) + ")" if not can_cast_to_float(comparison.value): values = f"'{values}'" return f"metadata['{comparison.attribute}'] {comparator} {values}"
[docs] def visit_structured_query( self, structured_query: StructuredQuery ) -> Tuple[str, dict]: if structured_query.filter is None: kwargs = {} else: tqL = f"SELECT * WHERE {structured_query.filter.accept(self)}" kwargs = {"tql": tqL} return structured_query.query, kwargs