Updated script that can be controled by Nodejs web app

lib/python3.13/site-packages/pandas/core/computation/engines.py

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+"""
+Engine classes for :func:`~pandas.eval`
+"""
+from __future__ import annotations
+
+import abc
+from typing import TYPE_CHECKING
+
+from pandas.errors import NumExprClobberingError
+
+from pandas.core.computation.align import (
+    align_terms,
+    reconstruct_object,
+)
+from pandas.core.computation.ops import (
+    MATHOPS,
+    REDUCTIONS,
+)
+
+from pandas.io.formats import printing
+
+if TYPE_CHECKING:
+    from pandas.core.computation.expr import Expr
+
+_ne_builtins = frozenset(MATHOPS + REDUCTIONS)
+
+
+def _check_ne_builtin_clash(expr: Expr) -> None:
+    """
+    Attempt to prevent foot-shooting in a helpful way.
+
+    Parameters
+    ----------
+    expr : Expr
+        Terms can contain
+    """
+    names = expr.names
+    overlap = names & _ne_builtins
+
+    if overlap:
+        s = ", ".join([repr(x) for x in overlap])
+        raise NumExprClobberingError(
+            f'Variables in expression "{expr}" overlap with builtins: ({s})'
+        )
+
+
+class AbstractEngine(metaclass=abc.ABCMeta):
+    """Object serving as a base class for all engines."""
+
+    has_neg_frac = False
+
+    def __init__(self, expr) -> None:
+        self.expr = expr
+        self.aligned_axes = None
+        self.result_type = None
+
+    def convert(self) -> str:
+        """
+        Convert an expression for evaluation.
+
+        Defaults to return the expression as a string.
+        """
+        return printing.pprint_thing(self.expr)
+
+    def evaluate(self) -> object:
+        """
+        Run the engine on the expression.
+
+        This method performs alignment which is necessary no matter what engine
+        is being used, thus its implementation is in the base class.
+
+        Returns
+        -------
+        object
+            The result of the passed expression.
+        """
+        if not self._is_aligned:
+            self.result_type, self.aligned_axes = align_terms(self.expr.terms)
+
+        # make sure no names in resolvers and locals/globals clash
+        res = self._evaluate()
+        return reconstruct_object(
+            self.result_type, res, self.aligned_axes, self.expr.terms.return_type
+        )
+
+    @property
+    def _is_aligned(self) -> bool:
+        return self.aligned_axes is not None and self.result_type is not None
+
+    @abc.abstractmethod
+    def _evaluate(self):
+        """
+        Return an evaluated expression.
+
+        Parameters
+        ----------
+        env : Scope
+            The local and global environment in which to evaluate an
+            expression.
+
+        Notes
+        -----
+        Must be implemented by subclasses.
+        """
+
+
+class NumExprEngine(AbstractEngine):
+    """NumExpr engine class"""
+
+    has_neg_frac = True
+
+    def _evaluate(self):
+        import numexpr as ne
+
+        # convert the expression to a valid numexpr expression
+        s = self.convert()
+
+        env = self.expr.env
+        scope = env.full_scope
+        _check_ne_builtin_clash(self.expr)
+        return ne.evaluate(s, local_dict=scope)
+
+
+class PythonEngine(AbstractEngine):
+    """
+    Evaluate an expression in Python space.
+
+    Mostly for testing purposes.
+    """
+
+    has_neg_frac = False
+
+    def evaluate(self):
+        return self.expr()
+
+    def _evaluate(self) -> None:
+        pass
+
+
+ENGINES: dict[str, type[AbstractEngine]] = {
+    "numexpr": NumExprEngine,
+    "python": PythonEngine,
+}