From 0200289621c47c47e115b058761e569a159273e9 Mon Sep 17 00:00:00 2001
From: topper-123 <terji78@gmail.com>
Date: Thu, 6 Jul 2017 23:24:38 +0100
Subject: [PATCH 1/4] Added tests for _get_dtype.

Added tests for ``pd.core.dtypes.common._get_dtype``.
---
 pandas/tests/dtypes/test_common.py | 39 ++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/pandas/tests/dtypes/test_common.py b/pandas/tests/dtypes/test_common.py
index ba510e68f9a21..506d02c7c4b07 100644
--- a/pandas/tests/dtypes/test_common.py
+++ b/pandas/tests/dtypes/test_common.py
@@ -524,3 +524,42 @@ def test_is_complex_dtype():
 
     assert com.is_complex_dtype(np.complex)
     assert com.is_complex_dtype(np.array([1 + 1j, 5]))
+
+
+@pytest.mark.parametrize('input_param,result', [
+    (int, np.dtype(int)),
+    ('int32', np.dtype('int32')),
+    (float, np.dtype(float)),
+    ('float64', np.dtype('float64')),
+    (np.dtype('float64'), np.dtype('float64')),
+    (str, np.dtype('<U')),
+    (pd.Series([1, 2], dtype=np.dtype('int16')), np.dtype('int16')),
+    (pd.Series(['a', 'b']), np.dtype(object)),
+    (pd.Index([1, 2]), np.dtype('int64')),
+    (pd.Index(['a', 'b']), np.dtype(object)),
+    ('category', 'category'),
+    (pd.Categorical(['a', 'b']).dtype, CategoricalDtype()),
+    pytest.mark.xfail((pd.Categorical(['a', 'b']), CategoricalDtype()),),
+    (pd.CategoricalIndex(['a', 'b']).dtype, CategoricalDtype()),
+    pytest.mark.xfail((pd.CategoricalIndex(['a', 'b']), CategoricalDtype()),),
+    (pd.DatetimeIndex([1, 2]), np.dtype('<M8[ns]')),
+    (pd.DatetimeIndex([1, 2]).dtype, np.dtype('<M8[ns]')),
+    ('<M8[ns]', np.dtype('<M8[ns]')),
+    ('datetime64[ns, Europe/London]', DatetimeTZDtype('ns', 'Europe/London')),
+    (pd.SparseSeries([1, 2], dtype='int32'), np.dtype('int32')),
+    (pd.SparseSeries([1, 2], dtype='int32').dtype, np.dtype('int32')),
+    (PeriodDtype(freq='D'), PeriodDtype(freq='D')),
+    ('period[D]', PeriodDtype(freq='D')),
+    (IntervalDtype(), IntervalDtype()),
+    ])
+def test__get_dtype(input_param, result):
+    assert com._get_dtype(input_param) == result
+
+
+@pytest.mark.parametrize('input_param', [None,
+                                   1, 1.2,
+                                   'random string',
+                                   pd.DataFrame([1, 2])])
+def test__get_dtype_fails(input_param):
+    # python objects
+    pytest.raises(TypeError, com._get_dtype, input_param)

From 2f668bd73e505719ea604862f0e1a79990d091d2 Mon Sep 17 00:00:00 2001
From: topper-123 <terji78@gmail.com>
Date: Fri, 7 Jul 2017 00:18:16 +0100
Subject: [PATCH 2/4] lint source code

---
 pandas/tests/dtypes/test_common.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/pandas/tests/dtypes/test_common.py b/pandas/tests/dtypes/test_common.py
index 506d02c7c4b07..7f445386a4025 100644
--- a/pandas/tests/dtypes/test_common.py
+++ b/pandas/tests/dtypes/test_common.py
@@ -551,15 +551,15 @@ def test_is_complex_dtype():
     (PeriodDtype(freq='D'), PeriodDtype(freq='D')),
     ('period[D]', PeriodDtype(freq='D')),
     (IntervalDtype(), IntervalDtype()),
-    ])
+])
 def test__get_dtype(input_param, result):
     assert com._get_dtype(input_param) == result
 
 
 @pytest.mark.parametrize('input_param', [None,
-                                   1, 1.2,
-                                   'random string',
-                                   pd.DataFrame([1, 2])])
+                                         1, 1.2,
+                                         'random string',
+                                         pd.DataFrame([1, 2])])
 def test__get_dtype_fails(input_param):
     # python objects
     pytest.raises(TypeError, com._get_dtype, input_param)

From 2b5385a9760280dbdbbf2af73e26fc1a43d86cd7 Mon Sep 17 00:00:00 2001
From: topper-123 <terji78@gmail.com>
Date: Sat, 8 Jul 2017 12:16:19 +0100
Subject: [PATCH 3/4] mark str, np.dtype('<U') as a xfail (experimentally)

mark str, np.dtype('<U') as a xfail (experimentally, because Travis complains)
---
 pandas/tests/dtypes/test_common.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/tests/dtypes/test_common.py b/pandas/tests/dtypes/test_common.py
index 7f445386a4025..d0860c93b0089 100644
--- a/pandas/tests/dtypes/test_common.py
+++ b/pandas/tests/dtypes/test_common.py
@@ -532,7 +532,7 @@ def test_is_complex_dtype():
     (float, np.dtype(float)),
     ('float64', np.dtype('float64')),
     (np.dtype('float64'), np.dtype('float64')),
-    (str, np.dtype('<U')),
+    pytest.mark.xfail(str, np.dtype('<U')),
     (pd.Series([1, 2], dtype=np.dtype('int16')), np.dtype('int16')),
     (pd.Series(['a', 'b']), np.dtype(object)),
     (pd.Index([1, 2]), np.dtype('int64')),

From 31cc08d11438ddacee88950e850f37e779e86d34 Mon Sep 17 00:00:00 2001
From: topper-123 <terji78@gmail.com>
Date: Sat, 8 Jul 2017 13:07:02 +0100
Subject: [PATCH 4/4] xfail on strings

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

diff --git a/pandas/tests/dtypes/test_common.py b/pandas/tests/dtypes/test_common.py
index d0860c93b0089..c32e8590c5675 100644
--- a/pandas/tests/dtypes/test_common.py
+++ b/pandas/tests/dtypes/test_common.py
@@ -532,7 +532,7 @@ def test_is_complex_dtype():
     (float, np.dtype(float)),
     ('float64', np.dtype('float64')),
     (np.dtype('float64'), np.dtype('float64')),
-    pytest.mark.xfail(str, np.dtype('<U')),
+    pytest.mark.xfail((str, np.dtype('<U')), ),
     (pd.Series([1, 2], dtype=np.dtype('int16')), np.dtype('int16')),
     (pd.Series(['a', 'b']), np.dtype(object)),
     (pd.Index([1, 2]), np.dtype('int64')),