Require numexpr 2.4.6

Author: Francesc Alted

doc/source/install.rst

@@ -226,7 +226,7 @@ Recommended Dependencies
 
 * `numexpr <https://github.com/pydata/numexpr>`__: for accelerating certain numerical operations.
   ``numexpr`` uses multiple cores as well as smart chunking and caching to achieve large speedups.
-  If installed, must be Version 2.1 or higher (excluding a buggy 2.4.4). Version 2.4.6 or higher is highly recommended.
+  If installed, must be Version 2.4.6 or higher.
 
 * `bottleneck <http://berkeleyanalytics.com/bottleneck>`__: for accelerating certain types of ``nan``
   evaluations. ``bottleneck`` uses specialized cython routines to achieve large speedups.

doc/source/whatsnew/v0.20.0.txt

@@ -9,7 +9,7 @@ users upgrade to this version.
 
 .. warning::
 
-   Due to important fixes and performance improvements, ``numexpr`` version is now required to be >= 2.6.2 and it will not be used at all if this requisite is not fullfilled (:issue:`15213`).
+   Due to important fixes and performance improvements, ``numexpr`` version is now required to be >= 2.4.6 and it will not be used at all if this requisite is not fullfilled (:issue:`15213`).
 
 Highlights include:
 

pandas/computation/__init__.py

@@ -7,13 +7,13 @@
 try:
     import numexpr as ne
     ver = ne.__version__
-    _NUMEXPR_INSTALLED = ver >= LooseVersion('2.6.2')
+    _NUMEXPR_INSTALLED = ver >= LooseVersion('2.4.6')
 
     if not _NUMEXPR_INSTALLED:
         warnings.warn(
             "The installed version of numexpr {ver} is not supported "
             "in pandas and will be not be used\nThe minimum supported "
-            "version is 2.6.2\n".format(ver=ver), UserWarning)
+            "version is 2.4.6\n".format(ver=ver), UserWarning)
 
 except ImportError:  # pragma: no cover
     pass