From 6d7834d973505ccdc0543242ba9eab8916fa0994 Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Wed, 19 Dec 2018 22:35:57 +0530
Subject: [PATCH 01/17] closes #24353

---
 pandas/core/computation/ops.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pandas/core/computation/ops.py b/pandas/core/computation/ops.py
index cbdb3525d5e88..c03bad1c0faa9 100644
--- a/pandas/core/computation/ops.py
+++ b/pandas/core/computation/ops.py
@@ -23,7 +23,8 @@
 
 _unary_math_ops = ('sin', 'cos', 'exp', 'log', 'expm1', 'log1p',
                    'sqrt', 'sinh', 'cosh', 'tanh', 'arcsin', 'arccos',
-                   'arctan', 'arccosh', 'arcsinh', 'arctanh', 'abs', 'log10')
+                   'arctan', 'arccosh', 'arcsinh', 'arctanh', 'abs', 'log10',
+                   'floor', 'ceil')
 _binary_math_ops = ('arctan2',)
 _mathops = _unary_math_ops + _binary_math_ops
 

From e92bd075905cfc10df14651f9bd0d1192a337baf Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Sun, 23 Dec 2018 17:58:55 +0530
Subject: [PATCH 02/17] update whatsnew

---
 doc/source/whatsnew/v0.24.0.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/source/whatsnew/v0.24.0.rst b/doc/source/whatsnew/v0.24.0.rst
index a84fd118061bc..f51235e1e1f58 100644
--- a/doc/source/whatsnew/v0.24.0.rst
+++ b/doc/source/whatsnew/v0.24.0.rst
@@ -1440,7 +1440,7 @@ Numeric
 - :meth:`Series.agg` can now handle numpy NaN-aware methods like :func:`numpy.nansum` (:issue:`19629`)
 - Bug in :meth:`Series.rank` and :meth:`DataFrame.rank` when ``pct=True`` and more than 2:sup:`24` rows are present resulted in percentages greater than 1.0 (:issue:`18271`)
 - Calls such as :meth:`DataFrame.round` with a non-unique :meth:`CategoricalIndex` now return expected data. Previously, data would be improperly duplicated (:issue:`21809`).
-- Added ``log10`` to the list of supported functions in :meth:`DataFrame.eval` (:issue:`24139`)
+- Added ``log10``, `floor` and `ceil` to the list of supported functions in :meth:`DataFrame.eval` (:issue:`24139`, :issue:`24353`)
 - Logical operations ``&, |, ^`` between :class:`Series` and :class:`Index` will no longer raise ``ValueError`` (:issue:`22092`)
 - Checking PEP 3141 numbers in :func:`~pandas.api.types.is_scalar` function returns ``True`` (:issue:`22903`)
 - Reduction methods like :meth:`Series.sum` now accept the default value of ``keepdims=False`` when called from a NumPy ufunc, rather than raising a ``TypeError``. Full support for ``keepdims`` has not been implemented (:issue:`24356`).

From f5b7c0e26c4b12a56fd61ca47cd500b0468fe61e Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Sun, 23 Dec 2018 17:59:51 +0530
Subject: [PATCH 03/17] raise error when function not supported by older
 version of numpy

---
 pandas/core/computation/ops.py        |  2 +-
 pandas/tests/computation/test_eval.py | 17 ++++++++++++++---
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/pandas/core/computation/ops.py b/pandas/core/computation/ops.py
index c03bad1c0faa9..f2baa6d3777b5 100644
--- a/pandas/core/computation/ops.py
+++ b/pandas/core/computation/ops.py
@@ -542,7 +542,7 @@ def __unicode__(self):
 class FuncNode(object):
 
     def __init__(self, name):
-        if name not in _mathops:
+        if name not in _mathops or not hasattr(np, name) :
             raise ValueError(
                 "\"{0}\" is not a supported function".format(name))
         self.name = name
diff --git a/pandas/tests/computation/test_eval.py b/pandas/tests/computation/test_eval.py
index 52945edb14e58..08820d5a290c4 100644
--- a/pandas/tests/computation/test_eval.py
+++ b/pandas/tests/computation/test_eval.py
@@ -1627,10 +1627,21 @@ def test_unary_functions(self):
         a = df.a
         for fn in self.unary_fns:
             expr = "{0}(a)".format(fn)
-            got = self.eval(expr)
             with np.errstate(all='ignore'):
-                expect = getattr(np, fn)(a)
-            tm.assert_series_equal(got, expect, check_names=False)
+                if hasattr(np, fn):
+                    got = self.eval(expr)
+                    expect = getattr(np, fn)(a)
+                    tm.assert_series_equal(got, expect, check_names=False)
+
+    def test_all_unary_functions_not_supported_in_numpy_112(self):
+        df = DataFrame({'a': np.random.randn(10)})
+        for fn in self.unary_fns:
+            expr = "{0}(a)".format(fn)
+            with np.errstate(all='ignore'):
+                if not hasattr(np, fn):
+                    msg = f"\"{fn}\" is not a supported function"
+                    with pytest.raises(ValueError, match=msg):
+                        self.eval(expr)
 
     def test_binary_functions(self):
         df = DataFrame({'a': np.random.randn(10),

From eb6c6217a7ee1fbb4074eb522bcbc3f1edcf4b22 Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Mon, 24 Dec 2018 22:06:37 +0530
Subject: [PATCH 04/17] Fix PEP8 issue

---
 pandas/core/computation/ops.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/core/computation/ops.py b/pandas/core/computation/ops.py
index f2baa6d3777b5..c5486e9c52b50 100644
--- a/pandas/core/computation/ops.py
+++ b/pandas/core/computation/ops.py
@@ -542,7 +542,7 @@ def __unicode__(self):
 class FuncNode(object):
 
     def __init__(self, name):
-        if name not in _mathops or not hasattr(np, name) :
+        if name not in _mathops or not hasattr(np, name):
             raise ValueError(
                 "\"{0}\" is not a supported function".format(name))
         self.name = name

From 7e8a643caff329b10a7214745c1b0c2ce66cb2a9 Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Mon, 24 Dec 2018 22:13:42 +0530
Subject: [PATCH 05/17] Fix compilation issue in py 2.7

---
 pandas/tests/computation/test_eval.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/tests/computation/test_eval.py b/pandas/tests/computation/test_eval.py
index 08820d5a290c4..64c08a9251f81 100644
--- a/pandas/tests/computation/test_eval.py
+++ b/pandas/tests/computation/test_eval.py
@@ -1639,7 +1639,7 @@ def test_all_unary_functions_not_supported_in_numpy_112(self):
             expr = "{0}(a)".format(fn)
             with np.errstate(all='ignore'):
                 if not hasattr(np, fn):
-                    msg = f"\"{fn}\" is not a supported function"
+                    msg = '"{0}" is not a supported function'.format(fn)
                     with pytest.raises(ValueError, match=msg):
                         self.eval(expr)
 

From 693449d67aacc14cdaf056acd780c9d31d2697af Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Mon, 24 Dec 2018 22:15:11 +0530
Subject: [PATCH 06/17] fix linting issue

---
 pandas/tests/computation/test_eval.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pandas/tests/computation/test_eval.py b/pandas/tests/computation/test_eval.py
index 64c08a9251f81..80df70808bb5e 100644
--- a/pandas/tests/computation/test_eval.py
+++ b/pandas/tests/computation/test_eval.py
@@ -1635,6 +1635,7 @@ def test_unary_functions(self):
 
     def test_all_unary_functions_not_supported_in_numpy_112(self):
         df = DataFrame({'a': np.random.randn(10)})
+        a = df.a
         for fn in self.unary_fns:
             expr = "{0}(a)".format(fn)
             with np.errstate(all='ignore'):

From 13568a6664fcaf21e87d6c9a076be5159f4a1200 Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Tue, 25 Dec 2018 00:22:56 +0530
Subject: [PATCH 07/17] numexpr less than 2.6.9

---
 pandas/core/computation/check.py       |  2 ++
 pandas/core/computation/expressions.py |  3 +-
 pandas/core/computation/ops.py         |  8 ++++-
 pandas/tests/computation/test_eval.py  | 45 +++++++++++++++++++-------
 4 files changed, 45 insertions(+), 13 deletions(-)

diff --git a/pandas/core/computation/check.py b/pandas/core/computation/check.py
index d2d5e018063ff..d17bcdc969bc6 100644
--- a/pandas/core/computation/check.py
+++ b/pandas/core/computation/check.py
@@ -3,11 +3,13 @@
 
 _NUMEXPR_INSTALLED = False
 _MIN_NUMEXPR_VERSION = "2.6.1"
+_ne_version_under_2_6_9 = None
 
 try:
     import numexpr as ne
     ver = LooseVersion(ne.__version__)
     _NUMEXPR_INSTALLED = ver >= LooseVersion(_MIN_NUMEXPR_VERSION)
+    _ne_version_under_2_6_9 = ver < LooseVersion('2.6.9')
 
     if not _NUMEXPR_INSTALLED:
         warnings.warn(
diff --git a/pandas/core/computation/expressions.py b/pandas/core/computation/expressions.py
index d44fae624a91c..684185ed21d0f 100644
--- a/pandas/core/computation/expressions.py
+++ b/pandas/core/computation/expressions.py
@@ -11,7 +11,7 @@
 import numpy as np
 
 import pandas.core.common as com
-from pandas.core.computation.check import _NUMEXPR_INSTALLED
+from pandas.core.computation.check import _NUMEXPR_INSTALLED, _ne_version_under_2_6_9
 from pandas.core.config import get_option
 
 if _NUMEXPR_INSTALLED:
@@ -20,6 +20,7 @@
 _TEST_MODE = None
 _TEST_RESULT = None
 _USE_NUMEXPR = _NUMEXPR_INSTALLED
+_ne_version_under2_6_9 = _ne_version_under_2_6_9
 _evaluate = None
 _where = None
 
diff --git a/pandas/core/computation/ops.py b/pandas/core/computation/ops.py
index c5486e9c52b50..d1e652004d574 100644
--- a/pandas/core/computation/ops.py
+++ b/pandas/core/computation/ops.py
@@ -15,6 +15,8 @@
 from pandas.core.base import StringMixin
 import pandas.core.common as com
 from pandas.core.computation.common import _ensure_decoded, _result_type_many
+from pandas.core.computation.expressions import (_NUMEXPR_INSTALLED,
+                                                 _ne_version_under_2_6_9)
 from pandas.core.computation.scope import _DEFAULT_GLOBALS
 
 from pandas.io.formats.printing import pprint_thing, pprint_thing_encoded
@@ -26,6 +28,7 @@
                    'arctan', 'arccosh', 'arcsinh', 'arctanh', 'abs', 'log10',
                    'floor', 'ceil')
 _binary_math_ops = ('arctan2',)
+_ops_for_ne_gt_2_6_9 = ('floor', 'ceil')
 _mathops = _unary_math_ops + _binary_math_ops
 
 
@@ -542,9 +545,12 @@ def __unicode__(self):
 class FuncNode(object):
 
     def __init__(self, name):
-        if name not in _mathops or not hasattr(np, name):
+        if name not in _mathops or (
+                _NUMEXPR_INSTALLED and _ne_version_under_2_6_9 and name in _ops_for_ne_gt_2_6_9
+        ):
             raise ValueError(
                 "\"{0}\" is not a supported function".format(name))
+
         self.name = name
         self.func = getattr(np, name)
 
diff --git a/pandas/tests/computation/test_eval.py b/pandas/tests/computation/test_eval.py
index 80df70808bb5e..2fe4894cef479 100644
--- a/pandas/tests/computation/test_eval.py
+++ b/pandas/tests/computation/test_eval.py
@@ -31,6 +31,9 @@
                                  assert_numpy_array_equal, assert_series_equal,
                                  assert_produces_warning)
 from pandas.compat import PY3, reduce
+from pandas.core.computation.expressions import (
+    _ne_version_under_2_6_9)
+
 
 _series_frame_incompatible = _bool_ops_syms
 _scalar_skip = 'in', 'not in'
@@ -54,6 +57,19 @@ def parser(request):
     return request.param
 
 
+@pytest.fixture
+def ne_lt_2_6_9():
+    if not _ne_version_under_2_6_9:
+        pytest.skip("numexpr is > 2.6.9")
+    return 'numexpr'
+
+@pytest.fixture
+def ne_gt_2_6_9():
+    if _ne_version_under_2_6_9:
+        pytest.skip("numexpr is < 2.6.9")
+    return 'numexpr'
+
+
 def engine_has_neg_frac(engine):
     return _engines[engine].has_neg_frac
 
@@ -1625,24 +1641,31 @@ def eval(self, *args, **kwargs):
     def test_unary_functions(self):
         df = DataFrame({'a': np.random.randn(10)})
         a = df.a
-        for fn in self.unary_fns:
+        unary_functions = [x for x in self.unary_fns
+                           if x not in ('floor', 'ceil')]
+        for fn in unary_functions:
             expr = "{0}(a)".format(fn)
+            got = self.eval(expr)
             with np.errstate(all='ignore'):
-                if hasattr(np, fn):
-                    got = self.eval(expr)
-                    expect = getattr(np, fn)(a)
-                    tm.assert_series_equal(got, expect, check_names=False)
+                expect = getattr(np, fn)(a)
+            tm.assert_series_equal(got, expect, check_names=False)
+
+    def test_floor_and_ceil_functions_raise_error(self, ne_lt_2_6_9):
+        for fn in ('floor', 'ceil'):
+            msg = "\"{0}\" is not a supported function".format(fn)
+            with pytest.raises(ValueError, match=msg):
+                expr = "{0}(100)".format(fn)
+                self.eval(expr)
 
-    def test_all_unary_functions_not_supported_in_numpy_112(self):
+    def test_floor_and_ceil_functions_evaluate_expressions(self, ne_gt_2_6_9):
         df = DataFrame({'a': np.random.randn(10)})
         a = df.a
-        for fn in self.unary_fns:
+        for fn in ('floor', 'ceil'):
             expr = "{0}(a)".format(fn)
+            got = self.eval(expr)
             with np.errstate(all='ignore'):
-                if not hasattr(np, fn):
-                    msg = '"{0}" is not a supported function'.format(fn)
-                    with pytest.raises(ValueError, match=msg):
-                        self.eval(expr)
+                expect = getattr(np, fn)(a)
+            tm.assert_series_equal(got, expect, check_names=False)
 
     def test_binary_functions(self):
         df = DataFrame({'a': np.random.randn(10),

From f963077ba627a63dff3884091cbfcd95ba564afa Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Tue, 25 Dec 2018 01:27:18 +0530
Subject: [PATCH 08/17] refactored to pass _NUMEXPR_VERSION

---
 pandas/core/computation/check.py       |  4 ++--
 pandas/core/computation/expressions.py |  3 +--
 pandas/core/computation/ops.py         | 13 +++++++------
 pandas/tests/computation/test_eval.py  | 10 +++++-----
 4 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/pandas/core/computation/check.py b/pandas/core/computation/check.py
index d17bcdc969bc6..762b811718493 100644
--- a/pandas/core/computation/check.py
+++ b/pandas/core/computation/check.py
@@ -3,13 +3,13 @@
 
 _NUMEXPR_INSTALLED = False
 _MIN_NUMEXPR_VERSION = "2.6.1"
-_ne_version_under_2_6_9 = None
+_NUMEXPR_VERSION = None
 
 try:
     import numexpr as ne
     ver = LooseVersion(ne.__version__)
     _NUMEXPR_INSTALLED = ver >= LooseVersion(_MIN_NUMEXPR_VERSION)
-    _ne_version_under_2_6_9 = ver < LooseVersion('2.6.9')
+    _NUMEXPR_VERSION = ver
 
     if not _NUMEXPR_INSTALLED:
         warnings.warn(
diff --git a/pandas/core/computation/expressions.py b/pandas/core/computation/expressions.py
index 684185ed21d0f..d44fae624a91c 100644
--- a/pandas/core/computation/expressions.py
+++ b/pandas/core/computation/expressions.py
@@ -11,7 +11,7 @@
 import numpy as np
 
 import pandas.core.common as com
-from pandas.core.computation.check import _NUMEXPR_INSTALLED, _ne_version_under_2_6_9
+from pandas.core.computation.check import _NUMEXPR_INSTALLED
 from pandas.core.config import get_option
 
 if _NUMEXPR_INSTALLED:
@@ -20,7 +20,6 @@
 _TEST_MODE = None
 _TEST_RESULT = None
 _USE_NUMEXPR = _NUMEXPR_INSTALLED
-_ne_version_under2_6_9 = _ne_version_under_2_6_9
 _evaluate = None
 _where = None
 
diff --git a/pandas/core/computation/ops.py b/pandas/core/computation/ops.py
index d1e652004d574..1909b29ccf4b6 100644
--- a/pandas/core/computation/ops.py
+++ b/pandas/core/computation/ops.py
@@ -2,6 +2,7 @@
 """
 
 from datetime import datetime
+from distutils.version import LooseVersion
 from functools import partial
 import operator as op
 
@@ -14,6 +15,7 @@
 import pandas as pd
 from pandas.core.base import StringMixin
 import pandas.core.common as com
+from pandas.core.computation.check import _NUMEXPR_VERSION
 from pandas.core.computation.common import _ensure_decoded, _result_type_many
 from pandas.core.computation.expressions import (_NUMEXPR_INSTALLED,
                                                  _ne_version_under_2_6_9)
@@ -25,10 +27,11 @@
 
 _unary_math_ops = ('sin', 'cos', 'exp', 'log', 'expm1', 'log1p',
                    'sqrt', 'sinh', 'cosh', 'tanh', 'arcsin', 'arccos',
-                   'arctan', 'arccosh', 'arcsinh', 'arctanh', 'abs', 'log10',
-                   'floor', 'ceil')
+                   'arctan', 'arccosh', 'arcsinh', 'arctanh', 'abs', 'log10')
 _binary_math_ops = ('arctan2',)
-_ops_for_ne_gt_2_6_9 = ('floor', 'ceil')
+if _NUMEXPR_INSTALLED and _NUMEXPR_VERSION >= LooseVersion('2.6.9'):
+    _unary_math_ops += ('floor', 'ceil')
+
 _mathops = _unary_math_ops + _binary_math_ops
 
 
@@ -545,9 +548,7 @@ def __unicode__(self):
 class FuncNode(object):
 
     def __init__(self, name):
-        if name not in _mathops or (
-                _NUMEXPR_INSTALLED and _ne_version_under_2_6_9 and name in _ops_for_ne_gt_2_6_9
-        ):
+        if name not in _mathops:
             raise ValueError(
                 "\"{0}\" is not a supported function".format(name))
 
diff --git a/pandas/tests/computation/test_eval.py b/pandas/tests/computation/test_eval.py
index 2fe4894cef479..4b5d36db340da 100644
--- a/pandas/tests/computation/test_eval.py
+++ b/pandas/tests/computation/test_eval.py
@@ -1,5 +1,6 @@
 import warnings
 import operator
+from distutils.version import LooseVersion
 from itertools import product
 
 import pytest
@@ -31,8 +32,7 @@
                                  assert_numpy_array_equal, assert_series_equal,
                                  assert_produces_warning)
 from pandas.compat import PY3, reduce
-from pandas.core.computation.expressions import (
-    _ne_version_under_2_6_9)
+from pandas.core.computation.check import _NUMEXPR_VERSION
 
 
 _series_frame_incompatible = _bool_ops_syms
@@ -59,13 +59,13 @@ def parser(request):
 
 @pytest.fixture
 def ne_lt_2_6_9():
-    if not _ne_version_under_2_6_9:
-        pytest.skip("numexpr is > 2.6.9")
+    if _NUMEXPR_INSTALLED and _NUMEXPR_VERSION >= LooseVersion('2.6.9'):
+        pytest.skip("numexpr is >= 2.6.9")
     return 'numexpr'
 
 @pytest.fixture
 def ne_gt_2_6_9():
-    if _ne_version_under_2_6_9:
+    if _NUMEXPR_INSTALLED and _NUMEXPR_VERSION < LooseVersion('2.6.9'):
         pytest.skip("numexpr is < 2.6.9")
     return 'numexpr'
 

From c8a8a02ba42aabda9a87d15a043e77dbd9fbb839 Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Tue, 25 Dec 2018 02:06:22 +0530
Subject: [PATCH 09/17] using self.unary_fns removed unused imports

---
 pandas/core/computation/ops.py        |  3 +--
 pandas/tests/computation/test_eval.py | 15 ++-------------
 2 files changed, 3 insertions(+), 15 deletions(-)

diff --git a/pandas/core/computation/ops.py b/pandas/core/computation/ops.py
index 1909b29ccf4b6..07dd66c179ed1 100644
--- a/pandas/core/computation/ops.py
+++ b/pandas/core/computation/ops.py
@@ -17,8 +17,7 @@
 import pandas.core.common as com
 from pandas.core.computation.check import _NUMEXPR_VERSION
 from pandas.core.computation.common import _ensure_decoded, _result_type_many
-from pandas.core.computation.expressions import (_NUMEXPR_INSTALLED,
-                                                 _ne_version_under_2_6_9)
+from pandas.core.computation.expressions import _NUMEXPR_INSTALLED
 from pandas.core.computation.scope import _DEFAULT_GLOBALS
 
 from pandas.io.formats.printing import pprint_thing, pprint_thing_encoded
diff --git a/pandas/tests/computation/test_eval.py b/pandas/tests/computation/test_eval.py
index 4b5d36db340da..3eeac293ea99c 100644
--- a/pandas/tests/computation/test_eval.py
+++ b/pandas/tests/computation/test_eval.py
@@ -1641,9 +1641,8 @@ def eval(self, *args, **kwargs):
     def test_unary_functions(self):
         df = DataFrame({'a': np.random.randn(10)})
         a = df.a
-        unary_functions = [x for x in self.unary_fns
-                           if x not in ('floor', 'ceil')]
-        for fn in unary_functions:
+
+        for fn in self.unary_fns:
             expr = "{0}(a)".format(fn)
             got = self.eval(expr)
             with np.errstate(all='ignore'):
@@ -1657,16 +1656,6 @@ def test_floor_and_ceil_functions_raise_error(self, ne_lt_2_6_9):
                 expr = "{0}(100)".format(fn)
                 self.eval(expr)
 
-    def test_floor_and_ceil_functions_evaluate_expressions(self, ne_gt_2_6_9):
-        df = DataFrame({'a': np.random.randn(10)})
-        a = df.a
-        for fn in ('floor', 'ceil'):
-            expr = "{0}(a)".format(fn)
-            got = self.eval(expr)
-            with np.errstate(all='ignore'):
-                expect = getattr(np, fn)(a)
-            tm.assert_series_equal(got, expect, check_names=False)
-
     def test_binary_functions(self):
         df = DataFrame({'a': np.random.randn(10),
                         'b': np.random.randn(10)})

From bdd9c6844c75c38a824eab8924eae50eadb919e6 Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Tue, 25 Dec 2018 14:56:37 +0530
Subject: [PATCH 10/17] fix linting issue

---
 pandas/tests/computation/test_eval.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pandas/tests/computation/test_eval.py b/pandas/tests/computation/test_eval.py
index 3eeac293ea99c..7ef7fdf1ba77f 100644
--- a/pandas/tests/computation/test_eval.py
+++ b/pandas/tests/computation/test_eval.py
@@ -63,6 +63,7 @@ def ne_lt_2_6_9():
         pytest.skip("numexpr is >= 2.6.9")
     return 'numexpr'
 
+
 @pytest.fixture
 def ne_gt_2_6_9():
     if _NUMEXPR_INSTALLED and _NUMEXPR_VERSION < LooseVersion('2.6.9'):

From 1e6ea3d8a2997eac577a1047d450d1bfd869af4b Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Tue, 25 Dec 2018 17:15:55 +0530
Subject: [PATCH 11/17] restored sys modules after import

---
 pandas/core/computation/check.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pandas/core/computation/check.py b/pandas/core/computation/check.py
index 762b811718493..d003b65809097 100644
--- a/pandas/core/computation/check.py
+++ b/pandas/core/computation/check.py
@@ -1,3 +1,4 @@
+import sys
 from distutils.version import LooseVersion
 import warnings
 
@@ -6,10 +7,12 @@
 _NUMEXPR_VERSION = None
 
 try:
+    modules = sys.modules.copy()
     import numexpr as ne
     ver = LooseVersion(ne.__version__)
     _NUMEXPR_INSTALLED = ver >= LooseVersion(_MIN_NUMEXPR_VERSION)
     _NUMEXPR_VERSION = ver
+    sys.modules = modules
 
     if not _NUMEXPR_INSTALLED:
         warnings.warn(
@@ -21,4 +24,4 @@
 except ImportError:  # pragma: no cover
     pass
 
-__all__ = ['_NUMEXPR_INSTALLED']
+__all__ = ['_NUMEXPR_INSTALLED', '_NUMEXPR_VERSION']

From a3a4b9e4acdf0596dfdd0c2164a0f068e588bef2 Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Tue, 25 Dec 2018 17:17:41 +0530
Subject: [PATCH 12/17] remove unused ne_gt_2_6_9

---
 pandas/tests/computation/test_eval.py | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/pandas/tests/computation/test_eval.py b/pandas/tests/computation/test_eval.py
index 7ef7fdf1ba77f..99125a1f04b0c 100644
--- a/pandas/tests/computation/test_eval.py
+++ b/pandas/tests/computation/test_eval.py
@@ -64,13 +64,6 @@ def ne_lt_2_6_9():
     return 'numexpr'
 
 
-@pytest.fixture
-def ne_gt_2_6_9():
-    if _NUMEXPR_INSTALLED and _NUMEXPR_VERSION < LooseVersion('2.6.9'):
-        pytest.skip("numexpr is < 2.6.9")
-    return 'numexpr'
-
-
 def engine_has_neg_frac(engine):
     return _engines[engine].has_neg_frac
 

From bc154e25e281087835d8931419685fcfefa519da Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Tue, 25 Dec 2018 17:47:55 +0530
Subject: [PATCH 13/17] Revert "restored sys modules after import"

This reverts commit 5933d5e794d0ff4661e1e7d341c98f7f0dd7b802.
---
 pandas/core/computation/check.py | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/pandas/core/computation/check.py b/pandas/core/computation/check.py
index d003b65809097..762b811718493 100644
--- a/pandas/core/computation/check.py
+++ b/pandas/core/computation/check.py
@@ -1,4 +1,3 @@
-import sys
 from distutils.version import LooseVersion
 import warnings
 
@@ -7,12 +6,10 @@
 _NUMEXPR_VERSION = None
 
 try:
-    modules = sys.modules.copy()
     import numexpr as ne
     ver = LooseVersion(ne.__version__)
     _NUMEXPR_INSTALLED = ver >= LooseVersion(_MIN_NUMEXPR_VERSION)
     _NUMEXPR_VERSION = ver
-    sys.modules = modules
 
     if not _NUMEXPR_INSTALLED:
         warnings.warn(
@@ -24,4 +21,4 @@
 except ImportError:  # pragma: no cover
     pass
 
-__all__ = ['_NUMEXPR_INSTALLED', '_NUMEXPR_VERSION']
+__all__ = ['_NUMEXPR_INSTALLED']

From caaf634ed03aa227fbd988f50be80efea7d53d7b Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Tue, 25 Dec 2018 17:58:45 +0530
Subject: [PATCH 14/17] exporting _NUMEXPR_VERSION as well

---
 pandas/core/computation/check.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/core/computation/check.py b/pandas/core/computation/check.py
index 762b811718493..da89bde56fe18 100644
--- a/pandas/core/computation/check.py
+++ b/pandas/core/computation/check.py
@@ -21,4 +21,4 @@
 except ImportError:  # pragma: no cover
     pass
 
-__all__ = ['_NUMEXPR_INSTALLED']
+__all__ = ['_NUMEXPR_INSTALLED', '_NUMEXPR_VERSION']

From bb07d26b0937f208766e728186138e239aafde73 Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Tue, 25 Dec 2018 22:46:29 +0530
Subject: [PATCH 15/17] fix imports

---
 pandas/core/computation/expressions.py | 2 +-
 pandas/core/computation/ops.py         | 3 +--
 pandas/tests/computation/test_eval.py  | 3 +--
 3 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/pandas/core/computation/expressions.py b/pandas/core/computation/expressions.py
index d44fae624a91c..3c67161cd9fea 100644
--- a/pandas/core/computation/expressions.py
+++ b/pandas/core/computation/expressions.py
@@ -11,7 +11,7 @@
 import numpy as np
 
 import pandas.core.common as com
-from pandas.core.computation.check import _NUMEXPR_INSTALLED
+from pandas.core.computation.check import _NUMEXPR_INSTALLED, _NUMEXPR_VERSION
 from pandas.core.config import get_option
 
 if _NUMEXPR_INSTALLED:
diff --git a/pandas/core/computation/ops.py b/pandas/core/computation/ops.py
index 07dd66c179ed1..604a5d61ee45a 100644
--- a/pandas/core/computation/ops.py
+++ b/pandas/core/computation/ops.py
@@ -15,9 +15,8 @@
 import pandas as pd
 from pandas.core.base import StringMixin
 import pandas.core.common as com
-from pandas.core.computation.check import _NUMEXPR_VERSION
+from pandas.core.computation.check import _NUMEXPR_INSTALLED, _NUMEXPR_VERSION
 from pandas.core.computation.common import _ensure_decoded, _result_type_many
-from pandas.core.computation.expressions import _NUMEXPR_INSTALLED
 from pandas.core.computation.scope import _DEFAULT_GLOBALS
 
 from pandas.io.formats.printing import pprint_thing, pprint_thing_encoded
diff --git a/pandas/tests/computation/test_eval.py b/pandas/tests/computation/test_eval.py
index 99125a1f04b0c..b8fa7b0247008 100644
--- a/pandas/tests/computation/test_eval.py
+++ b/pandas/tests/computation/test_eval.py
@@ -18,7 +18,7 @@
 from pandas.core.computation.engines import _engines, NumExprClobberingError
 from pandas.core.computation.expr import PythonExprVisitor, PandasExprVisitor
 from pandas.core.computation.expressions import (
-    _USE_NUMEXPR, _NUMEXPR_INSTALLED)
+    _USE_NUMEXPR, _NUMEXPR_INSTALLED, _NUMEXPR_VERSION)
 from pandas.core.computation.ops import (
     _binary_ops_dict,
     _special_case_arith_ops_syms,
@@ -32,7 +32,6 @@
                                  assert_numpy_array_equal, assert_series_equal,
                                  assert_produces_warning)
 from pandas.compat import PY3, reduce
-from pandas.core.computation.check import _NUMEXPR_VERSION
 
 
 _series_frame_incompatible = _bool_ops_syms

From 38115f6bc9bec24b7535f7459ff9eeb6be01f5e6 Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Tue, 25 Dec 2018 23:36:50 +0530
Subject: [PATCH 16/17] fixed imports

---
 pandas/core/computation/expressions.py | 2 +-
 pandas/tests/computation/test_eval.py  | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/pandas/core/computation/expressions.py b/pandas/core/computation/expressions.py
index 3c67161cd9fea..d44fae624a91c 100644
--- a/pandas/core/computation/expressions.py
+++ b/pandas/core/computation/expressions.py
@@ -11,7 +11,7 @@
 import numpy as np
 
 import pandas.core.common as com
-from pandas.core.computation.check import _NUMEXPR_INSTALLED, _NUMEXPR_VERSION
+from pandas.core.computation.check import _NUMEXPR_INSTALLED
 from pandas.core.config import get_option
 
 if _NUMEXPR_INSTALLED:
diff --git a/pandas/tests/computation/test_eval.py b/pandas/tests/computation/test_eval.py
index b8fa7b0247008..dec30c202f17b 100644
--- a/pandas/tests/computation/test_eval.py
+++ b/pandas/tests/computation/test_eval.py
@@ -15,10 +15,11 @@
 from pandas.util.testing import makeCustomDataframe as mkdf
 
 from pandas.core.computation import pytables
+from pandas.core.computation.check import _NUMEXPR_VERSION
 from pandas.core.computation.engines import _engines, NumExprClobberingError
 from pandas.core.computation.expr import PythonExprVisitor, PandasExprVisitor
 from pandas.core.computation.expressions import (
-    _USE_NUMEXPR, _NUMEXPR_INSTALLED, _NUMEXPR_VERSION)
+    _USE_NUMEXPR, _NUMEXPR_INSTALLED)
 from pandas.core.computation.ops import (
     _binary_ops_dict,
     _special_case_arith_ops_syms,

From 3ccb40c8608b4a41b2b16b566f94aeb31f66608f Mon Sep 17 00:00:00 2001
From: Anjana S <anjanas@thoughtworks.com>
Date: Sun, 30 Dec 2018 10:57:04 +0530
Subject: [PATCH 17/17] Fix numexpr version issue

---
 pandas/core/computation/ops.py        | 16 ++++++++++------
 pandas/tests/computation/test_eval.py | 20 +++++++++++++++++---
 2 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/pandas/core/computation/ops.py b/pandas/core/computation/ops.py
index 604a5d61ee45a..8c3218a976b6b 100644
--- a/pandas/core/computation/ops.py
+++ b/pandas/core/computation/ops.py
@@ -15,7 +15,6 @@
 import pandas as pd
 from pandas.core.base import StringMixin
 import pandas.core.common as com
-from pandas.core.computation.check import _NUMEXPR_INSTALLED, _NUMEXPR_VERSION
 from pandas.core.computation.common import _ensure_decoded, _result_type_many
 from pandas.core.computation.scope import _DEFAULT_GLOBALS
 
@@ -25,10 +24,10 @@
 
 _unary_math_ops = ('sin', 'cos', 'exp', 'log', 'expm1', 'log1p',
                    'sqrt', 'sinh', 'cosh', 'tanh', 'arcsin', 'arccos',
-                   'arctan', 'arccosh', 'arcsinh', 'arctanh', 'abs', 'log10')
+                   'arctan', 'arccosh', 'arcsinh', 'arctanh', 'abs', 'log10',
+                   'floor', 'ceil'
+                   )
 _binary_math_ops = ('arctan2',)
-if _NUMEXPR_INSTALLED and _NUMEXPR_VERSION >= LooseVersion('2.6.9'):
-    _unary_math_ops += ('floor', 'ceil')
 
 _mathops = _unary_math_ops + _binary_math_ops
 
@@ -544,9 +543,14 @@ def __unicode__(self):
 
 
 class FuncNode(object):
-
     def __init__(self, name):
-        if name not in _mathops:
+        from pandas.core.computation.check import (_NUMEXPR_INSTALLED,
+                                                   _NUMEXPR_VERSION)
+        if name not in _mathops or (
+                _NUMEXPR_INSTALLED and
+                _NUMEXPR_VERSION < LooseVersion('2.6.9') and
+                name in ('floor', 'ceil')
+        ):
             raise ValueError(
                 "\"{0}\" is not a supported function".format(name))
 
diff --git a/pandas/tests/computation/test_eval.py b/pandas/tests/computation/test_eval.py
index dec30c202f17b..1649c99384ef2 100644
--- a/pandas/tests/computation/test_eval.py
+++ b/pandas/tests/computation/test_eval.py
@@ -64,6 +64,18 @@ def ne_lt_2_6_9():
     return 'numexpr'
 
 
+@pytest.fixture
+def unary_fns_for_ne():
+    if _NUMEXPR_INSTALLED:
+        if _NUMEXPR_VERSION >= LooseVersion('2.6.9'):
+            return _unary_math_ops
+        else:
+            return tuple(x for x in _unary_math_ops
+                         if x not in ("floor", "ceil"))
+    else:
+        pytest.skip("numexpr is not present")
+
+
 def engine_has_neg_frac(engine):
     return _engines[engine].has_neg_frac
 
@@ -1632,18 +1644,20 @@ def eval(self, *args, **kwargs):
         kwargs['level'] = kwargs.pop('level', 0) + 1
         return pd.eval(*args, **kwargs)
 
-    def test_unary_functions(self):
+    def test_unary_functions(self, unary_fns_for_ne):
         df = DataFrame({'a': np.random.randn(10)})
         a = df.a
 
-        for fn in self.unary_fns:
+        for fn in unary_fns_for_ne:
             expr = "{0}(a)".format(fn)
             got = self.eval(expr)
             with np.errstate(all='ignore'):
                 expect = getattr(np, fn)(a)
             tm.assert_series_equal(got, expect, check_names=False)
 
-    def test_floor_and_ceil_functions_raise_error(self, ne_lt_2_6_9):
+    def test_floor_and_ceil_functions_raise_error(self,
+                                                  ne_lt_2_6_9,
+                                                  unary_fns_for_ne):
         for fn in ('floor', 'ceil'):
             msg = "\"{0}\" is not a supported function".format(fn)
             with pytest.raises(ValueError, match=msg):