DEPR: deprecate truediv param in pd.eval (pandas-dev#29812)

Author: jbrockmendel

doc/source/whatsnew/v1.0.0.rst

@@ -364,7 +364,7 @@ Deprecations
   value in ``idx`` of ``idx_val`` and a new value of ``val``, ``idx.set_value(arr, idx_val, val)``
   is equivalent to ``arr[idx.get_loc(idx_val)] = val``, which should be used instead (:issue:`28621`).
 - :func:`is_extension_type` is deprecated, :func:`is_extension_array_dtype` should be used instead (:issue:`29457`)
-
+- :func:`eval` keyword argument "truediv" is deprecated and will be removed in a future version (:issue:`29812`)
 
 .. _whatsnew_1000.prior_deprecations:
 

pandas/core/computation/engines.py

@@ -5,7 +5,7 @@
 import abc
 
 from pandas.core.computation.align import align_terms, reconstruct_object
-from pandas.core.computation.ops import UndefinedVariableError, _mathops, _reductions
+from pandas.core.computation.ops import _mathops, _reductions
 
 import pandas.io.formats.printing as printing
 
@@ -114,19 +114,10 @@ def _evaluate(self):
         # convert the expression to a valid numexpr expression
         s = self.convert()
 
-        try:
-            env = self.expr.env
-            scope = env.full_scope
-            truediv = scope["truediv"]
-            _check_ne_builtin_clash(self.expr)
-            return ne.evaluate(s, local_dict=scope, truediv=truediv)
-        except KeyError as e:
-            # python 3 compat kludge
-            try:
-                msg = e.message
-            except AttributeError:
-                msg = str(e)
-            raise UndefinedVariableError(msg)
+        env = self.expr.env
+        scope = env.full_scope
+        _check_ne_builtin_clash(self.expr)
+        return ne.evaluate(s, local_dict=scope)
 
 
 class PythonEngine(AbstractEngine):

pandas/core/computation/eval.py

@@ -7,6 +7,7 @@
 import tokenize
 import warnings
 
+from pandas._libs.lib import _no_default
 from pandas.util._validators import validate_bool_kwarg
 
 from pandas.core.computation.engines import _engines
@@ -169,7 +170,7 @@ def eval(
     expr,
     parser="pandas",
     engine=None,
-    truediv=True,
+    truediv=_no_default,
     local_dict=None,
     global_dict=None,
     resolvers=(),
@@ -219,6 +220,8 @@ def eval(
 
     truediv : bool, optional
         Whether to use true division, like in Python >= 3.
+        deprecated:: 1.0.0
+
     local_dict : dict or None, optional
         A dictionary of local variables, taken from locals() by default.
     global_dict : dict or None, optional
@@ -284,6 +287,14 @@ def eval(
 
     inplace = validate_bool_kwarg(inplace, "inplace")
 
+    if truediv is not _no_default:
+        warnings.warn(
+            "The `truediv` parameter in pd.eval is deprecated and will be "
+            "removed in a future version.",
+            FutureWarning,
+            stacklevel=2,
+        )
+
     if isinstance(expr, str):
         _check_expression(expr)
         exprs = [e.strip() for e in expr.splitlines() if e.strip() != ""]
@@ -317,7 +328,7 @@ def eval(
             target=target,
         )
 
-        parsed_expr = Expr(expr, engine=engine, parser=parser, env=env, truediv=truediv)
+        parsed_expr = Expr(expr, engine=engine, parser=parser, env=env)
 
         # construct the engine and evaluate the parsed expression
         eng = _engines[engine]

pandas/core/computation/expr.py

@@ -7,7 +7,7 @@
 import itertools as it
 import operator
 import tokenize
-from typing import Type
+from typing import Optional, Type
 
 import numpy as np
 
@@ -564,8 +564,7 @@ def visit_BinOp(self, node, **kwargs):
         return self._maybe_evaluate_binop(op, op_class, left, right)
 
     def visit_Div(self, node, **kwargs):
-        truediv = self.env.scope["truediv"]
-        return lambda lhs, rhs: Div(lhs, rhs, truediv)
+        return lambda lhs, rhs: Div(lhs, rhs)
 
     def visit_UnaryOp(self, node, **kwargs):
         op = self.visit(node.op)
@@ -813,18 +812,25 @@ class Expr:
     engine : str, optional, default 'numexpr'
     parser : str, optional, default 'pandas'
     env : Scope, optional, default None
-    truediv : bool, optional, default True
     level : int, optional, default 2
     """
 
+    env: Scope
+    engine: str
+    parser: str
+
     def __init__(
-        self, expr, engine="numexpr", parser="pandas", env=None, truediv=True, level=0
+        self,
+        expr,
+        engine: str = "numexpr",
+        parser: str = "pandas",
+        env: Optional[Scope] = None,
+        level: int = 0,
     ):
         self.expr = expr
         self.env = env or Scope(level=level + 1)
         self.engine = engine
         self.parser = parser
-        self.env.scope["truediv"] = truediv
         self._visitor = _parsers[parser](self.env, self.engine, self.parser)
         self.terms = self.parse()
 

pandas/core/computation/ops.py

@@ -391,9 +391,6 @@ def __call__(self, env):
         object
             The result of an evaluated expression.
         """
-        # handle truediv
-        if self.op == "/" and env.scope["truediv"]:
-            self.func = operator.truediv
 
         # recurse over the left/right nodes
         left = self.lhs(env)
@@ -505,12 +502,9 @@ class Div(BinOp):
     ----------
     lhs, rhs : Term or Op
         The Terms or Ops in the ``/`` expression.
-    truediv : bool
-        Whether or not to use true division. With Python 3 this happens
-        regardless of the value of ``truediv``.
     """
 
-    def __init__(self, lhs, rhs, truediv: bool, **kwargs):
+    def __init__(self, lhs, rhs, **kwargs):
         super().__init__("/", lhs, rhs, **kwargs)
 
         if not isnumeric(lhs.return_type) or not isnumeric(rhs.return_type):

pandas/tests/computation/test_eval.py

@@ -2006,6 +2006,23 @@ def test_inf(engine, parser):
     assert result == expected
 
 
+def test_truediv_deprecated(engine, parser):
+    # GH#29182
+    match = "The `truediv` parameter in pd.eval is deprecated"
+
+    with tm.assert_produces_warning(FutureWarning) as m:
+        pd.eval("1+1", engine=engine, parser=parser, truediv=True)
+
+    assert len(m) == 1
+    assert match in str(m[0].message)
+
+    with tm.assert_produces_warning(FutureWarning) as m:
+        pd.eval("1+1", engine=engine, parser=parser, truediv=False)
+
+    assert len(m) == 1
+    assert match in str(m[0].message)
+
+
 def test_negate_lt_eq_le(engine, parser):
     df = pd.DataFrame([[0, 10], [1, 20]], columns=["cat", "count"])
     expected = df[~(df.cat > 0)]