ENH: Move NumExprClobberingError to error/__init__.py per GH27656

doc/source/reference/testing.rst

@@ -35,6 +35,7 @@ Exceptions and warnings
    errors.MergeError
    errors.NullFrequencyError
    errors.NumbaUtilError
+   errors.NumExprClobberingError
    errors.OptionError
    errors.OutOfBoundsDatetime
    errors.OutOfBoundsTimedelta

doc/source/whatsnew/v1.5.0.rst

@@ -151,7 +151,7 @@ Other enhancements
 - A :class:`errors.PerformanceWarning` is now thrown when using ``string[pyarrow]`` dtype with methods that don't dispatch to ``pyarrow.compute`` methods (:issue:`42613`)
 - Added ``numeric_only`` argument to :meth:`Resampler.sum`, :meth:`Resampler.prod`, :meth:`Resampler.min`, :meth:`Resampler.max`, :meth:`Resampler.first`, and :meth:`Resampler.last` (:issue:`46442`)
 - ``times`` argument in :class:`.ExponentialMovingWindow` now accepts ``np.timedelta64`` (:issue:`47003`)
-- :class:`DataError`, :class:`SpecificationError`, :class:`SettingWithCopyError`, and :class:`SettingWithCopyWarning` are now exposed in ``pandas.errors`` (:issue:`27656`)
+- :class:`DataError`, :class:`SpecificationError`, :class:`SettingWithCopyError`, :class:`SettingWithCopyWarning`, and :class:`NumExprClobberingError` are now exposed in ``pandas.errors`` (:issue:`27656`)
 - Added ``check_like`` argument to :func:`testing.assert_series_equal` (:issue:`47247`)
 
 .. ---------------------------------------------------------------------------

pandas/core/computation/engines.py

@@ -5,6 +5,8 @@
 
 import abc
 
+from pandas.errors import NumExprClobberingError
+
 from pandas.core.computation.align import (
     align_terms,
     reconstruct_object,
@@ -20,10 +22,6 @@
 _ne_builtins = frozenset(MATHOPS + REDUCTIONS)
 
 
-class NumExprClobberingError(NameError):
-    pass
-
-
 def _check_ne_builtin_clash(expr: Expr) -> None:
     """
     Attempt to prevent foot-shooting in a helpful way.

pandas/errors/__init__.py

@@ -308,3 +308,21 @@ class SettingWithCopyWarning(Warning):
     >>> df.loc[0:3]['A'] = 'a' # doctest: +SKIP
     ... # SettingWithCopyWarning: A value is trying to be set on a copy of a...
     """
+
+
+class NumExprClobberingError(NameError):
+    """
+    Exception is raised when trying to use a built-in numexpr name as a variable name
+    in a method like query or eval. Eval will throw the error if the engine is set
+    to 'numexpr'. 'numexpr' is the default engine value for eval if the numexpr package
+    is installed.
+
+    Examples
+    --------
+    >>> df = pd.DataFrame({'abs': [1, 1, 1]})
+    >>> df.query("abs > 2") # doctest: +SKIP
+    ... # NumExprClobberingError: Variables in expression "(abs) > (2)" overlap...
+    >>> sin, a = 1, 2
+    >>> pd.eval("sin + a", engine='numexpr') # doctest: +SKIP
+    ... # NumExprClobberingError: Variables in expression "(sin) + (a)" overlap...
+    """

pandas/tests/computation/test_eval.py

@@ -9,7 +9,10 @@
 import numpy as np
 import pytest
 
-from pandas.errors import PerformanceWarning
+from pandas.errors import (
+    NumExprClobberingError,
+    PerformanceWarning,
+)
 import pandas.util._test_decorators as td
 
 from pandas.core.dtypes.common import (
@@ -27,10 +30,7 @@
 )
 import pandas._testing as tm
 from pandas.core.computation import pytables
-from pandas.core.computation.engines import (
-    ENGINES,
-    NumExprClobberingError,
-)
+from pandas.core.computation.engines import ENGINES
 import pandas.core.computation.expr as expr
 from pandas.core.computation.expr import (
     BaseExprVisitor,

pandas/tests/frame/test_query_eval.py

@@ -533,7 +533,7 @@ def test_query_doesnt_pickup_local(self):
             df.query("sin > 5", engine=engine, parser=parser)
 
     def test_query_builtin(self):
-        from pandas.core.computation.engines import NumExprClobberingError
+        from pandas.errors import NumExprClobberingError
 
         engine, parser = self.engine, self.parser
 

pandas/tests/test_errors.py

@@ -23,6 +23,7 @@
         "SpecificationError",
         "SettingWithCopyError",
         "SettingWithCopyWarning",
+        "NumExprClobberingError",
     ],
 )
 def test_exception_importable(exc):