BUG: read_sql_table can't find views

doc/source/whatsnew/v0.17.0.txt

@@ -137,11 +137,15 @@ Other enhancements
 - ``.as_blocks`` will now take a ``copy`` optional argument to return a copy of the data, default is to copy (no change in behavior from prior versions), (:issue:`9607`)
 
 - ``regex`` argument to ``DataFrame.filter`` now handles numeric column names instead of raising ``ValueError`` (:issue:`10384`).
+
 - ``pd.read_stata`` will now read Stata 118 type files. (:issue:`9882`)
 
 - ``pd.merge`` will now allow duplicate column names if they are not merged upon (:issue:`10639`).
 
 - ``pd.pivot`` will now allow passing index as ``None`` (:issue:`3962`).
+
+- ``read_sql_table`` will now allow reading from views (:issue:`10750`).
+
 - ``drop_duplicates`` and ``duplicated`` now accept ``keep`` keyword to target first, last, and all duplicates. ``take_last`` keyword is deprecated, see :ref:`deprecations <whatsnew_0170.deprecations>` (:issue:`6511`, :issue:`8505`)
 
 .. ipython :: python
@@ -151,6 +155,35 @@ Other enhancements
    s.drop_duplicates(keep='last')
    s.drop_duplicates(keep=False)
 
+- ``read_sql_table`` will now allow reading from views (:issue:`10750`).
+
+- ``concat`` will now inherit the existing series names (even when some are missing), if new ones are not provided through the ``keys`` argument (:issue:`10698`).
+
+  Previous Behavior:
+
+  .. code-block:: python
+
+     In [1]: foo = pd.Series([1,2], name='foo')
+     In [2]: bar = pd.Series([1,2])
+     In [3]: baz = pd.Series([4,5])
+     In [4] pd.concat([foo, bar, baz], 1)
+     Out[4]:
+           0  1  2
+        0  1  1  4
+        1  2  2  5
+
+  New Behavior:
+
+  .. ipython:: python
+
+    foo = pd.Series([1,2], name='foo')
+    bar = pd.Series([1,2])
+    baz = pd.Series([4,5])
+    pd.concat([foo, bar, baz], 1)
+
+- ``read_sql_table`` will now allow reading from views (:issue:`10750`).
+
+- ``read_sql_table`` will now allow reading from views (:issue:`10750`).
 
 .. _whatsnew_0170.api:
 
@@ -529,7 +562,6 @@ Deprecations
   =====================  =================================
 
 - ``Categorical.name`` was deprecated to make ``Categorical`` more ``numpy.ndarray`` like. Use ``Series(cat, name="whatever")`` instead (:issue:`10482`).
-- ``drop_duplicates`` and ``duplicated``'s ``take_last`` keyword was removed in favor of ``keep``. (:issue:`6511`, :issue:`8505`)
 
 .. _whatsnew_0170.prior_deprecations:
 
@@ -616,9 +648,6 @@ Bug Fixes
 
 
 - Bug in ``read_stata`` when reading a file with a different order set in ``columns`` (:issue:`10757`)
-- Bug in ``Categorical`` may not representing properly when category contains ``tz`` or ``Period`` (:issue:`10713`)
-- Bug in ``Categorical.__iter__`` may not returning correct ``datetime`` and ``Period`` (:issue:`10713`)
-
 
 - Reading "famafrench" data via ``DataReader`` results in HTTP 404 error because of the website url is changed (:issue:`10591`).
 - Bug in ``read_msgpack`` where DataFrame to decode has duplicate column names (:issue:`9618`)

pandas/io/sql.py

@@ -337,7 +337,7 @@ def read_sql_table(table_name, con, schema=None, index_col=None,
     from sqlalchemy.schema import MetaData
     meta = MetaData(con, schema=schema)
     try:
-        meta.reflect(only=[table_name])
+        meta.reflect(only=[table_name], views=True)
     except sqlalchemy.exc.InvalidRequestError:
         raise ValueError("Table %s not found" % table_name)
 

pandas/io/tests/test_sql.py

@@ -161,6 +161,12 @@
                 SELECT * FROM iris WHERE
                 "Name"=%(name)s AND "SepalLength"=%(length)s
                 """
+    },
+    'create_view': {
+        'sqlite': """
+                CREATE VIEW iris_view AS
+                SELECT * FROM iris;
+                """
     }
 }
 
@@ -244,6 +250,10 @@ def _load_iris_data(self):
             for row in r:
                 self._get_exec().execute(ins, row)
 
+    def _load_iris_view(self):
+        self.drop_table('iris_view')
+        self._get_exec().execute(SQL_STRINGS['create_view'][self.flavor])
+
     def _check_iris_loaded_frame(self, iris_frame):
         pytype = iris_frame.dtypes[0].type
         row = iris_frame.iloc[0]
@@ -482,6 +492,7 @@ class _TestSQLApi(PandasSQLTest):
     def setUp(self):
         self.conn = self.connect()
         self._load_iris_data()
+        self._load_iris_view()
         self._load_test1_data()
         self._load_test2_data()
         self._load_test3_data()
@@ -492,6 +503,11 @@ def test_read_sql_iris(self):
             "SELECT * FROM iris", self.conn)
         self._check_iris_loaded_frame(iris_frame)
 
+    def test_read_sql_view(self):
+        iris_frame = sql.read_sql_query(
+            "SELECT * FROM iris_view", self.conn)
+        self._check_iris_loaded_frame(iris_frame)
+
     def test_legacy_read_frame(self):
         with tm.assert_produces_warning(FutureWarning):
             iris_frame = sql.read_frame(

pandas/tools/merge.py

@@ -16,7 +16,7 @@
 from pandas.core.internals import (items_overlap_with_suffix,
                                    concatenate_block_managers)
 from pandas.util.decorators import Appender, Substitution
-from pandas.core.common import ABCSeries
+from pandas.core.common import ABCSeries, isnull
 from pandas.io.parsers import TextFileReader
 
 import pandas.core.common as com
@@ -896,8 +896,14 @@ def get_result(self):
                 data = dict(zip(range(len(self.objs)), self.objs))
                 index, columns = self.new_axes
                 tmpdf = DataFrame(data, index=index)
-                if columns is not None:
-                    tmpdf.columns = columns
+                # checks if the column variable already stores valid column names (because set via the 'key' argument
+                # in the 'concat' function call. If that's not the case, use the series names as column names
+                if columns.equals(Index(np.arange(len(self.objs)))):
+                    columns = np.array([ data[i].name for i in range(len(data)) ], dtype='object')
+                    indexer = isnull(columns)
+                    if indexer.any():
+                        columns[indexer] = np.arange(len(indexer[indexer]))
+                tmpdf.columns = columns
                 return tmpdf.__finalize__(self, method='concat')
 
         # combine block managers

pandas/tools/tests/test_merge.py

@@ -1797,6 +1797,15 @@ def test_concat_dataframe_keys_bug(self):
         self.assertEqual(list(result.columns), [('t1', 'value'),
                                                 ('t2', 'value')])
 
+    def test_concat_series_partial_columns_names(self):
+        foo = pd.Series([1,2], name='foo')
+        bar = pd.Series([1,2])
+        baz = pd.Series([4,5])
+
+        result = pd.concat([foo, bar, baz], 1)
+        expected = DataFrame({'foo' : [1,2], 0 : [1,2], 1 : [4,5]}, columns=['foo',0,1])
+        tm.assert_frame_equal(result, expected)
+
     def test_concat_dict(self):
         frames = {'foo': DataFrame(np.random.randn(4, 3)),
                   'bar': DataFrame(np.random.randn(4, 3)),
@@ -2330,7 +2339,7 @@ def test_concat_series_axis1(self):
 
         s2.name = None
         result = concat([s, s2], axis=1)
-        self.assertTrue(np.array_equal(result.columns, lrange(2)))
+        self.assertTrue(np.array_equal(result.columns, Index(['A', 0], dtype='object')))
 
         # must reindex, #2603
         s = Series(randn(3), index=['c', 'a', 'b'], name='A')
@@ -2431,7 +2440,7 @@ def test_concat_series_axis1_same_names_ignore_index(self):
         s2 = Series(randn(len(dates)), index=dates, name='value')
 
         result = concat([s1, s2], axis=1, ignore_index=True)
-        self.assertTrue(np.array_equal(result.columns, [0, 1]))
+        self.assertTrue(np.array_equal(result.columns, ['value', 'value']))
 
     def test_concat_iterables(self):
         from collections import deque, Iterable