From 19dc3042a25cf7ab5e54b77fa84f059c4971f244 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Wed, 12 Jun 2019 22:03:07 +0200
Subject: [PATCH 01/26] TST: add TestReadPyTablesHDF5 test scaffold

---
 pandas/tests/io/test_pytables.py | 84 ++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)

diff --git a/pandas/tests/io/test_pytables.py b/pandas/tests/io/test_pytables.py
index 299c0feb502be..cdc4d6b33dbc0 100644
--- a/pandas/tests/io/test_pytables.py
+++ b/pandas/tests/io/test_pytables.py
@@ -5,6 +5,7 @@
 from io import BytesIO
 import os
 import tempfile
+import time
 from warnings import catch_warnings, simplefilter
 
 import numpy as np
@@ -5177,3 +5178,86 @@ def test_dst_transitions(self):
                 store.append('df', df)
                 result = store.select('df')
                 assert_frame_equal(result, df)
+
+
+class TestReadPyTablesHDF5(Base):
+    """
+    A group of tests which covers reading HDF5 files written by plain PyTables
+    (not written by pandas).
+    """
+
+    def _create_simple_hdf5_file_with_pytables(self):
+
+        table_schema = {
+            'c0': tables.Time64Col(pos=0),
+            'c1': tables.StringCol(5, pos=1),
+            'c2': tables.UInt32Col(pos=2),
+        }
+
+        t0 = time.time()
+
+        testsamples = [
+            {'c0': t0, 'c1': 'aaaaa', 'c2': 1},
+            {'c0': t0 + 1, 'c1': 'bbbbb', 'c2': 2},
+            {'c0': t0 + 2, 'c1': 'ccccc', 'c2': 10**5},
+            {'c0': t0 + 3, 'c1': 'ddddd', 'c2': 4294967295},
+        ]
+
+        # This returns a path and does not open the file.
+        tmpfilepath = create_tempfile(self.path)
+        objectname = 'pandas_test_timeseries'
+
+        with tables.open_file(tmpfilepath, mode='w') as hf:
+            t = hf.create_table('/', name=objectname, description=table_schema)
+            for sample in testsamples:
+                for key, value in sample.items():
+                    t.row[key] = value
+                t.row.append()
+
+        return tmpfilepath, objectname, testsamples
+
+    def _compare(self, df, samples):
+        """Compare the reference `samples` with the contents in DataFrame `df`.
+        """
+        for idx, row in df.iterrows():
+            # Compare Time64Col values with tolerance.
+            tm.assert_almost_equal(samples[idx]['c0'], row['c0'])
+
+            # Compare a short string.
+            assert samples[idx]['c1'] == row['c1']
+
+            # Compare an unsigned 32 bit integer.
+            assert samples[idx]['c2'] == row['c2']
+
+    def test_read_complete(self):
+        path, objname, samples = self._create_simple_hdf5_file_with_pytables()
+
+        df = pd.read_hdf(path, key=objname)
+        self._compare(df, samples)
+
+    def test_read_with_start(self):
+        path, objname, samples = self._create_simple_hdf5_file_with_pytables()
+
+        # Currently this fails as of
+        # https://github.com/pandas-dev/pandas/issues/11188
+        with pytest.raises(ValueError, match='Shape of passed values is'):
+            df = pd.read_hdf(path, key=objname, start=1)
+            self._compare(df, samples[1:])
+
+    def test_read_with_stop(self):
+        path, objname, samples = self._create_simple_hdf5_file_with_pytables()
+
+        # Currently this fails as of
+        # https://github.com/pandas-dev/pandas/issues/11188
+        with pytest.raises(ValueError, match='Shape of passed values is'):
+            df = pd.read_hdf(path, key=objname, stop=1)
+            self._compare(df, samples[0:1])
+
+    def test_read_with_startstop(self):
+        path, objname, samples = self._create_simple_hdf5_file_with_pytables()
+
+        # Currently this fails as of
+        # https://github.com/pandas-dev/pandas/issues/11188
+        with pytest.raises(ValueError, match='Shape of passed values is'):
+            df = pd.read_hdf(path, key=objname, start=1, stop=2)
+            self._compare(df, samples[1:2])

From e9c7c39ddadd9ea3a6cf97cbe60aad288783c015 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Wed, 12 Jun 2019 23:27:46 +0200
Subject: [PATCH 02/26] BUG: this fixes #11188

---
 pandas/io/pytables.py            | 16 +++++++++++++++-
 pandas/tests/io/test_pytables.py | 31 ++++++++++---------------------
 2 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index 79d6d8563a162..15b260bbf5ef5 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -1456,6 +1456,11 @@ def __init__(self, store, s, func, where, nrows, start=None, stop=None,
                 stop = nrows
             stop = min(nrows, stop)
 
+            # Piggy-back normalized `nrows` (considering start and stop) onto
+            # PyTables tables object so that the GenericIndexCol constructor
+            # knows how large the index should be.
+            self.s.table._nrows_to_read = stop - start
+
         self.nrows = nrows
         self.start = start
         self.stop = stop
@@ -1816,7 +1821,16 @@ def is_indexed(self):
     def convert(self, values, nan_rep, encoding, errors):
         """ set the values from this selection: take = take ownership """
 
-        self.values = Int64Index(np.arange(self.table.nrows))
+        if hasattr(self.table, '_nrows_to_read'):
+            # The `_nrows_to_read` property is set on the table object by the
+            # code path invoked by the top-level `read_hdf()`, and calculated
+            # based on the start` and `stop` integer values. These values allow
+            # for a sub-selection and likewise the index size needs to be
+            # adjusted to the size of this sub-selection.
+            self.values = Int64Index(np.arange(self.table._nrows_to_read))
+        else:
+            self.values = Int64Index(np.arange(self.table.nrows))
+
         return self
 
     def get_attr(self):
diff --git a/pandas/tests/io/test_pytables.py b/pandas/tests/io/test_pytables.py
index cdc4d6b33dbc0..a4223ff606406 100644
--- a/pandas/tests/io/test_pytables.py
+++ b/pandas/tests/io/test_pytables.py
@@ -5231,33 +5231,22 @@ def _compare(self, df, samples):
 
     def test_read_complete(self):
         path, objname, samples = self._create_simple_hdf5_file_with_pytables()
-
-        df = pd.read_hdf(path, key=objname)
-        self._compare(df, samples)
+        self._compare(pd.read_hdf(path, key=objname), samples)
 
     def test_read_with_start(self):
         path, objname, samples = self._create_simple_hdf5_file_with_pytables()
-
-        # Currently this fails as of
-        # https://github.com/pandas-dev/pandas/issues/11188
-        with pytest.raises(ValueError, match='Shape of passed values is'):
-            df = pd.read_hdf(path, key=objname, start=1)
-            self._compare(df, samples[1:])
+        # This is a regression test for pandas-dev/pandas/issues/11188
+        self._compare(pd.read_hdf(path, key=objname, start=1), samples[1:])
 
     def test_read_with_stop(self):
         path, objname, samples = self._create_simple_hdf5_file_with_pytables()
-
-        # Currently this fails as of
-        # https://github.com/pandas-dev/pandas/issues/11188
-        with pytest.raises(ValueError, match='Shape of passed values is'):
-            df = pd.read_hdf(path, key=objname, stop=1)
-            self._compare(df, samples[0:1])
+        # This is a regression test for pandas-dev/pandas/issues/11188
+        self._compare(pd.read_hdf(path, key=objname, stop=1), samples[0:1])
 
     def test_read_with_startstop(self):
         path, objname, samples = self._create_simple_hdf5_file_with_pytables()
-
-        # Currently this fails as of
-        # https://github.com/pandas-dev/pandas/issues/11188
-        with pytest.raises(ValueError, match='Shape of passed values is'):
-            df = pd.read_hdf(path, key=objname, start=1, stop=2)
-            self._compare(df, samples[1:2])
+        # This is a regression test for pandas-dev/pandas/issues/11188
+        self._compare(
+            pd.read_hdf(path, key=objname, start=1, stop=2),
+            samples[1:2]
+        )

From b7a082ab7f46140bb7c32396a20ba6254806b585 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 14 Jun 2019 11:30:35 +0200
Subject: [PATCH 03/26] CLN: do not piggyback idx size on table obj

---
 pandas/io/pytables.py | 28 ++++++++++------------------
 1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index 15b260bbf5ef5..fd3e7dfcce543 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -1456,11 +1456,6 @@ def __init__(self, store, s, func, where, nrows, start=None, stop=None,
                 stop = nrows
             stop = min(nrows, stop)
 
-            # Piggy-back normalized `nrows` (considering start and stop) onto
-            # PyTables tables object so that the GenericIndexCol constructor
-            # knows how large the index should be.
-            self.s.table._nrows_to_read = stop - start
-
         self.nrows = nrows
         self.start = start
         self.stop = stop
@@ -1629,7 +1624,7 @@ def infer(self, handler):
         new_self.read_metadata(handler)
         return new_self
 
-    def convert(self, values, nan_rep, encoding, errors):
+    def convert(self, values, nan_rep, encoding, errors, **kwargs):
         """ set the values from this selection: take = take ownership """
 
         # values is a recarray
@@ -1818,18 +1813,13 @@ class GenericIndexCol(IndexCol):
     def is_indexed(self):
         return False
 
-    def convert(self, values, nan_rep, encoding, errors):
+    def convert(self, values, nan_rep, encoding, errors, **kwargs):
         """ set the values from this selection: take = take ownership """
 
-        if hasattr(self.table, '_nrows_to_read'):
-            # The `_nrows_to_read` property is set on the table object by the
-            # code path invoked by the top-level `read_hdf()`, and calculated
-            # based on the start` and `stop` integer values. These values allow
-            # for a sub-selection and likewise the index size needs to be
-            # adjusted to the size of this sub-selection.
-            self.values = Int64Index(np.arange(self.table._nrows_to_read))
-        else:
-            self.values = Int64Index(np.arange(self.table.nrows))
+        start = kwargs.get('start', 0)
+        stop = kwargs.get('stop', self.table.nrows)
+        stop = min(stop, self.table.nrows)
+        self.values = Int64Index(np.arange(stop - start))
 
         return self
 
@@ -2173,7 +2163,7 @@ def validate_attr(self, append):
                 raise ValueError("appended items dtype do not match existing "
                                  "items dtype in table!")
 
-    def convert(self, values, nan_rep, encoding, errors):
+    def convert(self, values, nan_rep, encoding, errors, **kwargs):
         """set the data from this selection (and convert to the correct dtype
         if we can)
         """
@@ -3445,8 +3435,10 @@ def read_axes(self, where, **kwargs):
         # convert the data
         for a in self.axes:
             a.set_info(self.info)
+            # `kwargs` may contain `start` and `stop` arguments if passed to
+            # `store.select()`. If set they determine the index size.
             a.convert(values, nan_rep=self.nan_rep, encoding=self.encoding,
-                      errors=self.errors)
+                      errors=self.errors, **kwargs)
 
         return True
 

From 964cba1a47b67d02fcd1780c82d9e58d604086bd Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Wed, 12 Jun 2019 23:35:16 +0200
Subject: [PATCH 04/26] DOC: update whatsnew for #11188

---
 doc/source/whatsnew/v0.25.0.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/source/whatsnew/v0.25.0.rst b/doc/source/whatsnew/v0.25.0.rst
index 77b689569d57f..f695ad61ff209 100644
--- a/doc/source/whatsnew/v0.25.0.rst
+++ b/doc/source/whatsnew/v0.25.0.rst
@@ -699,6 +699,7 @@ I/O
 - Bug in :func:`read_csv` not properly interpreting the UTF8 encoded filenames on Windows on Python 3.6+ (:issue:`15086`)
 - Improved performance in :meth:`pandas.read_stata` and :class:`pandas.io.stata.StataReader` when converting columns that have missing values (:issue:`25772`)
 - Bug in :meth:`DataFrame.to_html` where header numbers would ignore display options when rounding (:issue:`17280`)
+- Bug in :func:`read_hdf` where the `start` and `stop` arguments would raise a ``ValueError`` indicating an index size mismatch (:issue:`11188`)
 - Bug in :func:`read_hdf` not properly closing store after a ``KeyError`` is raised (:issue:`25766`)
 - Bug in ``read_csv`` which would not raise ``ValueError`` if a column index in ``usecols`` was out of bounds (:issue:`25623`)
 - Improved the explanation for the failure when value labels are repeated in Stata dta files and suggested work-arounds (:issue:`25772`)

From 04b8423a297513078a25f2e3b27e1ef687a6af4c Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 14 Jun 2019 21:41:04 +0200
Subject: [PATCH 05/26] DOC: improve changelog (squash later)

---
 doc/source/whatsnew/v0.25.0.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/source/whatsnew/v0.25.0.rst b/doc/source/whatsnew/v0.25.0.rst
index f695ad61ff209..467cb5a40213c 100644
--- a/doc/source/whatsnew/v0.25.0.rst
+++ b/doc/source/whatsnew/v0.25.0.rst
@@ -699,7 +699,7 @@ I/O
 - Bug in :func:`read_csv` not properly interpreting the UTF8 encoded filenames on Windows on Python 3.6+ (:issue:`15086`)
 - Improved performance in :meth:`pandas.read_stata` and :class:`pandas.io.stata.StataReader` when converting columns that have missing values (:issue:`25772`)
 - Bug in :meth:`DataFrame.to_html` where header numbers would ignore display options when rounding (:issue:`17280`)
-- Bug in :func:`read_hdf` where the `start` and `stop` arguments would raise a ``ValueError`` indicating an index size mismatch (:issue:`11188`)
+- Bug in :func:`read_hdf` where reading a table from an HDF5 file written directly with PyTables fails with a ``ValueError`` when using a sub-selection via the ``start`` or ``stop`` arguments (:issue:`11188`)
 - Bug in :func:`read_hdf` not properly closing store after a ``KeyError`` is raised (:issue:`25766`)
 - Bug in ``read_csv`` which would not raise ``ValueError`` if a column index in ``usecols`` was out of bounds (:issue:`25623`)
 - Improved the explanation for the failure when value labels are repeated in Stata dta files and suggested work-arounds (:issue:`25772`)

From 7d200a5aaa35ff98b07a554da910fe4f54ad45e2 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 14 Jun 2019 21:52:23 +0200
Subject: [PATCH 06/26] squash: remove kwargs, add a bit of docstring

---
 pandas/io/pytables.py | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index fd3e7dfcce543..cc1b4ddd4ea86 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -1624,7 +1624,7 @@ def infer(self, handler):
         new_self.read_metadata(handler)
         return new_self
 
-    def convert(self, values, nan_rep, encoding, errors, **kwargs):
+    def convert(self, values, nan_rep, encoding, errors, start=None, stop=None):
         """ set the values from this selection: take = take ownership """
 
         # values is a recarray
@@ -1813,11 +1813,21 @@ class GenericIndexCol(IndexCol):
     def is_indexed(self):
         return False
 
-    def convert(self, values, nan_rep, encoding, errors, **kwargs):
-        """ set the values from this selection: take = take ownership """
+    def convert(self, values, nan_rep, encoding, errors, start=None, stop=None):
+        """ set the values from this selection: take = take ownership
+
+        Parameters
+        ----------
+
+        start : int, optional
+            Table row number: the start of the sub-selection.
+        stop : int, optional
+            Table row number: the end of the sub-selection. Values larger than
+            the underlying table's row count are normalized to that.
+        """
 
-        start = kwargs.get('start', 0)
-        stop = kwargs.get('stop', self.table.nrows)
+        start = start if start is not None else 0
+        stop = stop if stop is not None else self.table.nrows
         stop = min(stop, self.table.nrows)
         self.values = Int64Index(np.arange(stop - start))
 
@@ -2163,7 +2173,7 @@ def validate_attr(self, append):
                 raise ValueError("appended items dtype do not match existing "
                                  "items dtype in table!")
 
-    def convert(self, values, nan_rep, encoding, errors, **kwargs):
+    def convert(self, values, nan_rep, encoding, errors, start=None, stop=None):
         """set the data from this selection (and convert to the correct dtype
         if we can)
         """

From 70e78c91ac0731eedd9f6d159828368886074e16 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 14 Jun 2019 22:29:24 +0200
Subject: [PATCH 07/26] squash: rework tests (use fixture, assert_frame_equal)

---
 pandas/tests/io/test_pytables.py | 102 +++++++++++++++----------------
 1 file changed, 49 insertions(+), 53 deletions(-)

diff --git a/pandas/tests/io/test_pytables.py b/pandas/tests/io/test_pytables.py
index a4223ff606406..ac4638a525fbb 100644
--- a/pandas/tests/io/test_pytables.py
+++ b/pandas/tests/io/test_pytables.py
@@ -5180,73 +5180,69 @@ def test_dst_transitions(self):
                 assert_frame_equal(result, df)
 
 
-class TestReadPyTablesHDF5(Base):
-    """
-    A group of tests which covers reading HDF5 files written by plain PyTables
-    (not written by pandas).
-    """
-
-    def _create_simple_hdf5_file_with_pytables(self):
-
-        table_schema = {
-            'c0': tables.Time64Col(pos=0),
-            'c1': tables.StringCol(5, pos=1),
-            'c2': tables.UInt32Col(pos=2),
-        }
+@pytest.fixture(scope='module')
+def pytables_hdf5_file():
+    """Use PyTables to create a simple HDF5 file."""
 
-        t0 = time.time()
+    table_schema = {
+        'c0': tables.Time64Col(pos=0),
+        'c1': tables.StringCol(5, pos=1),
+        'c2': tables.Int64Col(pos=2),
+    }
 
-        testsamples = [
-            {'c0': t0, 'c1': 'aaaaa', 'c2': 1},
-            {'c0': t0 + 1, 'c1': 'bbbbb', 'c2': 2},
-            {'c0': t0 + 2, 'c1': 'ccccc', 'c2': 10**5},
-            {'c0': t0 + 3, 'c1': 'ddddd', 'c2': 4294967295},
-        ]
+    t0 = time.time()
 
-        # This returns a path and does not open the file.
-        tmpfilepath = create_tempfile(self.path)
-        objectname = 'pandas_test_timeseries'
+    testsamples = [
+        {'c0': t0, 'c1': 'aaaaa', 'c2': 1},
+        {'c0': t0 + 1, 'c1': 'bbbbb', 'c2': 2},
+        {'c0': t0 + 2, 'c1': 'ccccc', 'c2': 10**5},
+        {'c0': t0 + 3, 'c1': 'ddddd', 'c2': 4294967295},
+    ]
 
-        with tables.open_file(tmpfilepath, mode='w') as hf:
-            t = hf.create_table('/', name=objectname, description=table_schema)
-            for sample in testsamples:
-                for key, value in sample.items():
-                    t.row[key] = value
-                t.row.append()
+    # This returns a path and does not open the file.
+    tmpfilepath = create_tempfile('pytables_hdf5_file')
+    objectname = 'pandas_test_timeseries'
 
-        return tmpfilepath, objectname, testsamples
+    with tables.open_file(tmpfilepath, mode='w') as hf:
+        t = hf.create_table('/', name=objectname, description=table_schema)
+        for sample in testsamples:
+            for key, value in sample.items():
+                t.row[key] = value
+            t.row.append()
 
-    def _compare(self, df, samples):
-        """Compare the reference `samples` with the contents in DataFrame `df`.
-        """
-        for idx, row in df.iterrows():
-            # Compare Time64Col values with tolerance.
-            tm.assert_almost_equal(samples[idx]['c0'], row['c0'])
+    return tmpfilepath, objectname, pd.DataFrame(testsamples)
 
-            # Compare a short string.
-            assert samples[idx]['c1'] == row['c1']
 
-            # Compare an unsigned 32 bit integer.
-            assert samples[idx]['c2'] == row['c2']
+class TestReadPyTablesHDF5(Base):
+    """
+    A group of tests which covers reading HDF5 files written by plain PyTables
+    (not written by pandas).
+    """
 
-    def test_read_complete(self):
-        path, objname, samples = self._create_simple_hdf5_file_with_pytables()
-        self._compare(pd.read_hdf(path, key=objname), samples)
+    def test_read_complete(self, pytables_hdf5_file):
+        path, objname, expected_df = pytables_hdf5_file
+        assert_frame_equal(pd.read_hdf(path, key=objname), expected_df)
 
-    def test_read_with_start(self):
-        path, objname, samples = self._create_simple_hdf5_file_with_pytables()
+    def test_read_with_start(self, pytables_hdf5_file):
+        path, objname, expected_df = pytables_hdf5_file
         # This is a regression test for pandas-dev/pandas/issues/11188
-        self._compare(pd.read_hdf(path, key=objname, start=1), samples[1:])
+        assert_frame_equal(
+            pd.read_hdf(path, key=objname, start=1),
+            expected_df[1:].reset_index(drop=True)
+        )
 
-    def test_read_with_stop(self):
-        path, objname, samples = self._create_simple_hdf5_file_with_pytables()
+    def test_read_with_stop(self, pytables_hdf5_file):
+        path, objname, expected_df = pytables_hdf5_file
         # This is a regression test for pandas-dev/pandas/issues/11188
-        self._compare(pd.read_hdf(path, key=objname, stop=1), samples[0:1])
+        assert_frame_equal(
+            pd.read_hdf(path, key=objname, stop=1),
+            expected_df[:1].reset_index(drop=True)
+        )
 
-    def test_read_with_startstop(self):
-        path, objname, samples = self._create_simple_hdf5_file_with_pytables()
+    def test_read_with_startstop(self, pytables_hdf5_file):
+        path, objname, expected_df = pytables_hdf5_file
         # This is a regression test for pandas-dev/pandas/issues/11188
-        self._compare(
+        assert_frame_equal(
             pd.read_hdf(path, key=objname, start=1, stop=2),
-            samples[1:2]
+            expected_df[1:2].reset_index(drop=True)
         )

From e7eb30a4440b6752f4a96e5a907112e142335941 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Tue, 18 Jun 2019 12:47:42 +0200
Subject: [PATCH 08/26] squash: address line length errors

---
 pandas/io/pytables.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index cc1b4ddd4ea86..d82a90cd47560 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -1624,7 +1624,8 @@ def infer(self, handler):
         new_self.read_metadata(handler)
         return new_self
 
-    def convert(self, values, nan_rep, encoding, errors, start=None, stop=None):
+    def convert(self, values, nan_rep, encoding, errors, start=None,
+                stop=None):
         """ set the values from this selection: take = take ownership """
 
         # values is a recarray
@@ -1813,7 +1814,8 @@ class GenericIndexCol(IndexCol):
     def is_indexed(self):
         return False
 
-    def convert(self, values, nan_rep, encoding, errors, start=None, stop=None):
+    def convert(self, values, nan_rep, encoding, errors, start=None,
+                stop=None):
         """ set the values from this selection: take = take ownership
 
         Parameters
@@ -2173,7 +2175,8 @@ def validate_attr(self, append):
                 raise ValueError("appended items dtype do not match existing "
                                  "items dtype in table!")
 
-    def convert(self, values, nan_rep, encoding, errors, start=None, stop=None):
+    def convert(self, values, nan_rep, encoding, errors, start=None,
+                stop=None):
         """set the data from this selection (and convert to the correct dtype
         if we can)
         """

From 5b881d8c64346ced22b603e7165c7dd5b658f6c0 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Tue, 18 Jun 2019 12:52:05 +0200
Subject: [PATCH 09/26] squash: pytables.py: remove one assignment

---
 pandas/io/pytables.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index d82a90cd47560..5ad278ffc55c4 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -1829,8 +1829,8 @@ def convert(self, values, nan_rep, encoding, errors, start=None,
         """
 
         start = start if start is not None else 0
-        stop = stop if stop is not None else self.table.nrows
-        stop = min(stop, self.table.nrows)
+        stop = min(stop, self.table.nrows) \
+            if stop is not None else self.table.nrows
         self.values = Int64Index(np.arange(stop - start))
 
         return self

From 96411118c240ab5e35ae8353ad0a9fc48917ae64 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Wed, 19 Jun 2019 12:29:01 +0200
Subject: [PATCH 10/26] squash: tests: result/expected, Base, fixture scope

---
 pandas/tests/io/test_pytables.py | 37 ++++++++++++++++----------------
 1 file changed, 18 insertions(+), 19 deletions(-)

diff --git a/pandas/tests/io/test_pytables.py b/pandas/tests/io/test_pytables.py
index ac4638a525fbb..8a3166a6dba6a 100644
--- a/pandas/tests/io/test_pytables.py
+++ b/pandas/tests/io/test_pytables.py
@@ -5180,7 +5180,7 @@ def test_dst_transitions(self):
                 assert_frame_equal(result, df)
 
 
-@pytest.fixture(scope='module')
+@pytest.fixture()
 def pytables_hdf5_file():
     """Use PyTables to create a simple HDF5 file."""
 
@@ -5213,36 +5213,35 @@ def pytables_hdf5_file():
     return tmpfilepath, objectname, pd.DataFrame(testsamples)
 
 
-class TestReadPyTablesHDF5(Base):
+class TestReadPyTablesHDF5:
     """
     A group of tests which covers reading HDF5 files written by plain PyTables
     (not written by pandas).
     """
 
     def test_read_complete(self, pytables_hdf5_file):
-        path, objname, expected_df = pytables_hdf5_file
-        assert_frame_equal(pd.read_hdf(path, key=objname), expected_df)
+        path, objname, df = pytables_hdf5_file
+        result = pd.read_hdf(path, key=objname)
+        expected = df
+        assert_frame_equal(result, expected)
 
     def test_read_with_start(self, pytables_hdf5_file):
-        path, objname, expected_df = pytables_hdf5_file
+        path, objname, df = pytables_hdf5_file
         # This is a regression test for pandas-dev/pandas/issues/11188
-        assert_frame_equal(
-            pd.read_hdf(path, key=objname, start=1),
-            expected_df[1:].reset_index(drop=True)
-        )
+        result = pd.read_hdf(path, key=objname, start=1)
+        expected = df[1:].reset_index(drop=True)
+        assert_frame_equal(result, expected)
 
     def test_read_with_stop(self, pytables_hdf5_file):
-        path, objname, expected_df = pytables_hdf5_file
+        path, objname, df = pytables_hdf5_file
         # This is a regression test for pandas-dev/pandas/issues/11188
-        assert_frame_equal(
-            pd.read_hdf(path, key=objname, stop=1),
-            expected_df[:1].reset_index(drop=True)
-        )
+        result = pd.read_hdf(path, key=objname, stop=1)
+        expected = df[:1].reset_index(drop=True)
+        assert_frame_equal(result, expected)
 
     def test_read_with_startstop(self, pytables_hdf5_file):
-        path, objname, expected_df = pytables_hdf5_file
+        path, objname, df = pytables_hdf5_file
         # This is a regression test for pandas-dev/pandas/issues/11188
-        assert_frame_equal(
-            pd.read_hdf(path, key=objname, start=1, stop=2),
-            expected_df[1:2].reset_index(drop=True)
-        )
+        result = pd.read_hdf(path, key=objname, start=1, stop=2)
+        expected = df[1:2].reset_index(drop=True)
+        assert_frame_equal(result, expected)

From d2a9882d309f9006190db3e8245a1608a057718f Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Wed, 19 Jun 2019 12:37:31 +0200
Subject: [PATCH 11/26] CLN: s/existing/exiting

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

diff --git a/pandas/tests/io/test_pytables.py b/pandas/tests/io/test_pytables.py
index 8a3166a6dba6a..90da18e1d7f56 100644
--- a/pandas/tests/io/test_pytables.py
+++ b/pandas/tests/io/test_pytables.py
@@ -106,7 +106,7 @@ def ensure_clean_store(path, mode='a', complevel=None, complib=None,
 def ensure_clean_path(path):
     """
     return essentially a named temporary file that is not opened
-    and deleted on existing; if path is a list, then create and
+    and deleted on exiting; if path is a list, then create and
     return list of filenames
     """
     try:

From aa834730f1b9192cb86da1dcf2bc6261b9110da6 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Wed, 19 Jun 2019 12:52:01 +0200
Subject: [PATCH 12/26] TST: use ensure_clean_path context manager

---
 pandas/tests/io/test_pytables.py | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/pandas/tests/io/test_pytables.py b/pandas/tests/io/test_pytables.py
index 90da18e1d7f56..fd5dc870d2be3 100644
--- a/pandas/tests/io/test_pytables.py
+++ b/pandas/tests/io/test_pytables.py
@@ -5199,18 +5199,18 @@ def pytables_hdf5_file():
         {'c0': t0 + 3, 'c1': 'ddddd', 'c2': 4294967295},
     ]
 
-    # This returns a path and does not open the file.
-    tmpfilepath = create_tempfile('pytables_hdf5_file')
-    objectname = 'pandas_test_timeseries'
-
-    with tables.open_file(tmpfilepath, mode='w') as hf:
-        t = hf.create_table('/', name=objectname, description=table_schema)
-        for sample in testsamples:
-            for key, value in sample.items():
-                t.row[key] = value
-            t.row.append()
-
-    return tmpfilepath, objectname, pd.DataFrame(testsamples)
+    objname = 'pandas_test_timeseries'
+
+    with ensure_clean_path('pytables_hdf5_file') as path:
+        # The `ensure_clean_path` context mgr removes the temp file upon exit.
+        with tables.open_file(path, mode='w') as f:
+            t = f.create_table('/', name=objname, description=table_schema)
+            for sample in testsamples:
+                for key, value in sample.items():
+                    t.row[key] = value
+                t.row.append()
+
+        yield path, objname, pd.DataFrame(testsamples)
 
 
 class TestReadPyTablesHDF5:

From 065054f5f635155f223429454ef9414b3354254b Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Wed, 19 Jun 2019 13:13:43 +0200
Subject: [PATCH 13/26] squash: do not use line cont backslash

---
 pandas/io/pytables.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index 5ad278ffc55c4..fec4ca447f667 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -1829,8 +1829,8 @@ def convert(self, values, nan_rep, encoding, errors, start=None,
         """
 
         start = start if start is not None else 0
-        stop = min(stop, self.table.nrows) \
-            if stop is not None else self.table.nrows
+        stop = (min(stop, self.table.nrows)
+            if stop is not None else self.table.nrows)
         self.values = Int64Index(np.arange(stop - start))
 
         return self

From 9cc85ce75daac2c70f33234717c4da47b4b7f972 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Wed, 19 Jun 2019 13:32:56 +0200
Subject: [PATCH 14/26] squash: pass start/stop explicitly into a.convert()

---
 pandas/io/pytables.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index fec4ca447f667..f7ae1db90551f 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -3451,7 +3451,8 @@ def read_axes(self, where, **kwargs):
             # `kwargs` may contain `start` and `stop` arguments if passed to
             # `store.select()`. If set they determine the index size.
             a.convert(values, nan_rep=self.nan_rep, encoding=self.encoding,
-                      errors=self.errors, **kwargs)
+                      errors=self.errors, start=kwargs.get('start'),
+                      stop=kwargs.get('stop'))
 
         return True
 

From cd69c0b414cc80a8ce579704eefcf7233cf1125d Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Wed, 19 Jun 2019 13:46:40 +0200
Subject: [PATCH 15/26] DOC: add some docstring

---
 pandas/io/pytables.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index f7ae1db90551f..a43433190a501 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -1821,6 +1821,14 @@ def convert(self, values, nan_rep, encoding, errors, start=None,
         Parameters
         ----------
 
+        values :
+            Expected to be passed but ignored in this implementation.
+        nan_rep :
+            Expected to be passed but ignored in this implementation.
+        encoding:
+            Expected to be passed but ignored in this implementation.
+        errors:
+            Expected to be passed but ignored in this implementation.
         start : int, optional
             Table row number: the start of the sub-selection.
         stop : int, optional

From a9c6f15ccc2d9bcd9f4e8c26f95d4c857b858b7c Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Wed, 19 Jun 2019 14:16:19 +0200
Subject: [PATCH 16/26] squash: flake8 error

---
 pandas/io/pytables.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index a43433190a501..673c91d7ff7ff 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -1838,7 +1838,7 @@ def convert(self, values, nan_rep, encoding, errors, start=None,
 
         start = start if start is not None else 0
         stop = (min(stop, self.table.nrows)
-            if stop is not None else self.table.nrows)
+                if stop is not None else self.table.nrows)
         self.values = Int64Index(np.arange(stop - start))
 
         return self

From 8adf459d6a5e6ecb6056745226fd42385632b478 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 21 Jun 2019 10:30:32 +0200
Subject: [PATCH 17/26] squash: change docstrings one more time

---
 pandas/io/pytables.py | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index 673c91d7ff7ff..17d580bae5cf1 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -1821,14 +1821,10 @@ def convert(self, values, nan_rep, encoding, errors, start=None,
         Parameters
         ----------
 
-        values :
-            Expected to be passed but ignored in this implementation.
-        nan_rep :
-            Expected to be passed but ignored in this implementation.
-        encoding:
-            Expected to be passed but ignored in this implementation.
-        errors:
-            Expected to be passed but ignored in this implementation.
+        values : np.ndarray
+        nan_rep : str
+        encoding : str
+        errors : str
         start : int, optional
             Table row number: the start of the sub-selection.
         stop : int, optional

From aed78ffc2c7fdcd5020c2770b08051af1014253e Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 21 Jun 2019 10:33:54 +0200
Subject: [PATCH 18/26] squash: tests: cleanup

---
 pandas/tests/io/test_pytables.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/pandas/tests/io/test_pytables.py b/pandas/tests/io/test_pytables.py
index fd5dc870d2be3..2b97e6c2b661e 100644
--- a/pandas/tests/io/test_pytables.py
+++ b/pandas/tests/io/test_pytables.py
@@ -5,7 +5,6 @@
 from io import BytesIO
 import os
 import tempfile
-import time
 from warnings import catch_warnings, simplefilter
 
 import numpy as np
@@ -5180,7 +5179,7 @@ def test_dst_transitions(self):
                 assert_frame_equal(result, df)
 
 
-@pytest.fixture()
+@pytest.fixture
 def pytables_hdf5_file():
     """Use PyTables to create a simple HDF5 file."""
 
@@ -5190,7 +5189,7 @@ def pytables_hdf5_file():
         'c2': tables.Int64Col(pos=2),
     }
 
-    t0 = time.time()
+    t0 = 1561105000.0
 
     testsamples = [
         {'c0': t0, 'c1': 'aaaaa', 'c2': 1},

From 53dba1a06a279c2bec8774ba1daa7ae6aac10132 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 21 Jun 2019 11:25:07 +0200
Subject: [PATCH 19/26] TST: move tests to io/pytables/test_compat.py

---
 pandas/tests/io/pytables/test_compat.py | 105 ++++++++++++++++++++++++
 pandas/tests/io/test_pytables.py        |  67 ---------------
 2 files changed, 105 insertions(+), 67 deletions(-)
 create mode 100644 pandas/tests/io/pytables/test_compat.py

diff --git a/pandas/tests/io/pytables/test_compat.py b/pandas/tests/io/pytables/test_compat.py
new file mode 100644
index 0000000000000..ba5878802b032
--- /dev/null
+++ b/pandas/tests/io/pytables/test_compat.py
@@ -0,0 +1,105 @@
+import os
+import tempfile
+from contextlib import contextmanager
+
+import pytest
+
+import pandas as pd
+
+from pandas.util.testing import assert_frame_equal
+
+
+tables = pytest.importorskip('tables')
+
+
+def safe_remove(path):
+    if path is not None:
+        try:
+            os.remove(path)
+        except OSError:
+            pass
+
+
+def create_tempfile(path):
+    return os.path.join(tempfile.gettempdir(), path)
+
+
+@contextmanager
+def ensure_clean_path(path):
+    try:
+        if isinstance(path, list):
+            filenames = [create_tempfile(p) for p in path]
+            yield filenames
+        else:
+            filenames = [create_tempfile(path)]
+            yield filenames[0]
+    finally:
+        for f in filenames:
+            safe_remove(f)
+
+
+@pytest.fixture
+def pytables_hdf5_file():
+    """Use PyTables to create a simple HDF5 file."""
+
+    table_schema = {
+        'c0': tables.Time64Col(pos=0),
+        'c1': tables.StringCol(5, pos=1),
+        'c2': tables.Int64Col(pos=2),
+    }
+
+    t0 = 1561105000.0
+
+    testsamples = [
+        {'c0': t0, 'c1': 'aaaaa', 'c2': 1},
+        {'c0': t0 + 1, 'c1': 'bbbbb', 'c2': 2},
+        {'c0': t0 + 2, 'c1': 'ccccc', 'c2': 10**5},
+        {'c0': t0 + 3, 'c1': 'ddddd', 'c2': 4294967295},
+    ]
+
+    objname = 'pandas_test_timeseries'
+
+    with ensure_clean_path('pytables_hdf5_file') as path:
+        # The `ensure_clean_path` context mgr removes the temp file upon exit.
+        with tables.open_file(path, mode='w') as f:
+            t = f.create_table('/', name=objname, description=table_schema)
+            for sample in testsamples:
+                for key, value in sample.items():
+                    t.row[key] = value
+                t.row.append()
+
+        yield path, objname, pd.DataFrame(testsamples)
+
+
+class TestReadPyTablesHDF5:
+    """
+    A group of tests which covers reading HDF5 files written by plain PyTables
+    (not written by pandas).
+    """
+
+    def test_read_complete(self, pytables_hdf5_file):
+        path, objname, df = pytables_hdf5_file
+        result = pd.read_hdf(path, key=objname)
+        expected = df
+        assert_frame_equal(result, expected)
+
+    def test_read_with_start(self, pytables_hdf5_file):
+        path, objname, df = pytables_hdf5_file
+        # This is a regression test for pandas-dev/pandas/issues/11188
+        result = pd.read_hdf(path, key=objname, start=1)
+        expected = df[1:].reset_index(drop=True)
+        assert_frame_equal(result, expected)
+
+    def test_read_with_stop(self, pytables_hdf5_file):
+        path, objname, df = pytables_hdf5_file
+        # This is a regression test for pandas-dev/pandas/issues/11188
+        result = pd.read_hdf(path, key=objname, stop=1)
+        expected = df[:1].reset_index(drop=True)
+        assert_frame_equal(result, expected)
+
+    def test_read_with_startstop(self, pytables_hdf5_file):
+        path, objname, df = pytables_hdf5_file
+        # This is a regression test for pandas-dev/pandas/issues/11188
+        result = pd.read_hdf(path, key=objname, start=1, stop=2)
+        expected = df[1:2].reset_index(drop=True)
+        assert_frame_equal(result, expected)
diff --git a/pandas/tests/io/test_pytables.py b/pandas/tests/io/test_pytables.py
index 2b97e6c2b661e..ef9dbc63d873d 100644
--- a/pandas/tests/io/test_pytables.py
+++ b/pandas/tests/io/test_pytables.py
@@ -5177,70 +5177,3 @@ def test_dst_transitions(self):
                 store.append('df', df)
                 result = store.select('df')
                 assert_frame_equal(result, df)
-
-
-@pytest.fixture
-def pytables_hdf5_file():
-    """Use PyTables to create a simple HDF5 file."""
-
-    table_schema = {
-        'c0': tables.Time64Col(pos=0),
-        'c1': tables.StringCol(5, pos=1),
-        'c2': tables.Int64Col(pos=2),
-    }
-
-    t0 = 1561105000.0
-
-    testsamples = [
-        {'c0': t0, 'c1': 'aaaaa', 'c2': 1},
-        {'c0': t0 + 1, 'c1': 'bbbbb', 'c2': 2},
-        {'c0': t0 + 2, 'c1': 'ccccc', 'c2': 10**5},
-        {'c0': t0 + 3, 'c1': 'ddddd', 'c2': 4294967295},
-    ]
-
-    objname = 'pandas_test_timeseries'
-
-    with ensure_clean_path('pytables_hdf5_file') as path:
-        # The `ensure_clean_path` context mgr removes the temp file upon exit.
-        with tables.open_file(path, mode='w') as f:
-            t = f.create_table('/', name=objname, description=table_schema)
-            for sample in testsamples:
-                for key, value in sample.items():
-                    t.row[key] = value
-                t.row.append()
-
-        yield path, objname, pd.DataFrame(testsamples)
-
-
-class TestReadPyTablesHDF5:
-    """
-    A group of tests which covers reading HDF5 files written by plain PyTables
-    (not written by pandas).
-    """
-
-    def test_read_complete(self, pytables_hdf5_file):
-        path, objname, df = pytables_hdf5_file
-        result = pd.read_hdf(path, key=objname)
-        expected = df
-        assert_frame_equal(result, expected)
-
-    def test_read_with_start(self, pytables_hdf5_file):
-        path, objname, df = pytables_hdf5_file
-        # This is a regression test for pandas-dev/pandas/issues/11188
-        result = pd.read_hdf(path, key=objname, start=1)
-        expected = df[1:].reset_index(drop=True)
-        assert_frame_equal(result, expected)
-
-    def test_read_with_stop(self, pytables_hdf5_file):
-        path, objname, df = pytables_hdf5_file
-        # This is a regression test for pandas-dev/pandas/issues/11188
-        result = pd.read_hdf(path, key=objname, stop=1)
-        expected = df[:1].reset_index(drop=True)
-        assert_frame_equal(result, expected)
-
-    def test_read_with_startstop(self, pytables_hdf5_file):
-        path, objname, df = pytables_hdf5_file
-        # This is a regression test for pandas-dev/pandas/issues/11188
-        result = pd.read_hdf(path, key=objname, start=1, stop=2)
-        expected = df[1:2].reset_index(drop=True)
-        assert_frame_equal(result, expected)

From dfec26ef2abf0cae8f0ab1582f13c11b9d1dcf92 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 21 Jun 2019 11:41:12 +0200
Subject: [PATCH 20/26] TST: use pytest fixture instead of ensure_clean_path

---
 pandas/tests/io/pytables/test_compat.py | 54 ++++++++-----------------
 1 file changed, 17 insertions(+), 37 deletions(-)

diff --git a/pandas/tests/io/pytables/test_compat.py b/pandas/tests/io/pytables/test_compat.py
index ba5878802b032..2e456ecb384fd 100644
--- a/pandas/tests/io/pytables/test_compat.py
+++ b/pandas/tests/io/pytables/test_compat.py
@@ -12,35 +12,13 @@
 tables = pytest.importorskip('tables')
 
 
-def safe_remove(path):
-    if path is not None:
-        try:
-            os.remove(path)
-        except OSError:
-            pass
-
-
-def create_tempfile(path):
-    return os.path.join(tempfile.gettempdir(), path)
-
-
-@contextmanager
-def ensure_clean_path(path):
-    try:
-        if isinstance(path, list):
-            filenames = [create_tempfile(p) for p in path]
-            yield filenames
-        else:
-            filenames = [create_tempfile(path)]
-            yield filenames[0]
-    finally:
-        for f in filenames:
-            safe_remove(f)
-
-
 @pytest.fixture
-def pytables_hdf5_file():
-    """Use PyTables to create a simple HDF5 file."""
+def pytables_hdf5_file(tmp_path):
+    """Use PyTables to create a simple HDF5 file.
+
+    There is no need for temporary file cleanup, pytest makes sure that there is
+    no collision between tests and that storage needs to not grow indefinitely.
+    """
 
     table_schema = {
         'c0': tables.Time64Col(pos=0),
@@ -59,16 +37,18 @@ def pytables_hdf5_file():
 
     objname = 'pandas_test_timeseries'
 
-    with ensure_clean_path('pytables_hdf5_file') as path:
-        # The `ensure_clean_path` context mgr removes the temp file upon exit.
-        with tables.open_file(path, mode='w') as f:
-            t = f.create_table('/', name=objname, description=table_schema)
-            for sample in testsamples:
-                for key, value in sample.items():
-                    t.row[key] = value
-                t.row.append()
+    # The `tmp_path` fixture provides a temporary directory unique to the
+    # individual test invocation. Create a file in there.
+    h5path = tmp_path / 'written_with_pytables.h5'
+
+    with tables.open_file(h5path, mode='w') as f:
+        t = f.create_table('/', name=objname, description=table_schema)
+        for sample in testsamples:
+            for key, value in sample.items():
+                t.row[key] = value
+            t.row.append()
 
-        yield path, objname, pd.DataFrame(testsamples)
+    return h5path, objname, pd.DataFrame(testsamples)
 
 
 class TestReadPyTablesHDF5:

From b9421af7a9da997e327632fb0e7d7b7df0c963bd Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 21 Jun 2019 13:27:28 +0200
Subject: [PATCH 21/26] squash: address linter errors

---
 pandas/tests/io/pytables/test_compat.py | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/pandas/tests/io/pytables/test_compat.py b/pandas/tests/io/pytables/test_compat.py
index 2e456ecb384fd..075188382720d 100644
--- a/pandas/tests/io/pytables/test_compat.py
+++ b/pandas/tests/io/pytables/test_compat.py
@@ -1,7 +1,3 @@
-import os
-import tempfile
-from contextlib import contextmanager
-
 import pytest
 
 import pandas as pd
@@ -16,8 +12,9 @@
 def pytables_hdf5_file(tmp_path):
     """Use PyTables to create a simple HDF5 file.
 
-    There is no need for temporary file cleanup, pytest makes sure that there is
-    no collision between tests and that storage needs to not grow indefinitely.
+    There is no need for temporary file cleanup, pytest makes sure that there
+    is no collision between tests and that storage needs to not grow
+    indefinitely.
     """
 
     table_schema = {

From 9c0e96b0b99646bbbc220fd1faec73fdd2baa367 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 21 Jun 2019 13:34:05 +0200
Subject: [PATCH 22/26] squash: pass path as text

---
 pandas/tests/io/pytables/test_compat.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/tests/io/pytables/test_compat.py b/pandas/tests/io/pytables/test_compat.py
index 075188382720d..b2eddfe924533 100644
--- a/pandas/tests/io/pytables/test_compat.py
+++ b/pandas/tests/io/pytables/test_compat.py
@@ -38,7 +38,7 @@ def pytables_hdf5_file(tmp_path):
     # individual test invocation. Create a file in there.
     h5path = tmp_path / 'written_with_pytables.h5'
 
-    with tables.open_file(h5path, mode='w') as f:
+    with tables.open_file(str(h5path), mode='w') as f:
         t = f.create_table('/', name=objname, description=table_schema)
         for sample in testsamples:
             for key, value in sample.items():

From 79bed6a7b74233d4010569e8f16aae812fb5511f Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 21 Jun 2019 13:57:50 +0200
Subject: [PATCH 23/26] squash: tests: improve code comment

---
 pandas/tests/io/pytables/test_compat.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/pandas/tests/io/pytables/test_compat.py b/pandas/tests/io/pytables/test_compat.py
index b2eddfe924533..c8e5b76cafa2c 100644
--- a/pandas/tests/io/pytables/test_compat.py
+++ b/pandas/tests/io/pytables/test_compat.py
@@ -12,9 +12,11 @@
 def pytables_hdf5_file(tmp_path):
     """Use PyTables to create a simple HDF5 file.
 
-    There is no need for temporary file cleanup, pytest makes sure that there
-    is no collision between tests and that storage needs to not grow
-    indefinitely.
+    There is no need for temporary file cleanup: pytest's `tmp_path` fixture
+    guarantees file system isolation between tests, retains files for later
+    inspection and then removes them in a rolling fashion so that the storage
+    space consumption does not grow indefinitely with the number of test runner
+    invocations.
     """
 
     table_schema = {

From bca6ee64b23625adb60c6a294708d5274936fada Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 21 Jun 2019 14:42:45 +0200
Subject: [PATCH 24/26] squash: use ensure_clean_path again

---
 pandas/tests/io/pytables/test_compat.py | 32 ++++++++++---------------
 1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/pandas/tests/io/pytables/test_compat.py b/pandas/tests/io/pytables/test_compat.py
index c8e5b76cafa2c..abe7987c581ba 100644
--- a/pandas/tests/io/pytables/test_compat.py
+++ b/pandas/tests/io/pytables/test_compat.py
@@ -1,23 +1,17 @@
 import pytest
 
 import pandas as pd
-
 from pandas.util.testing import assert_frame_equal
 
+from pandas.tests.io.test_pytables import ensure_clean_path
+
 
 tables = pytest.importorskip('tables')
 
 
 @pytest.fixture
 def pytables_hdf5_file(tmp_path):
-    """Use PyTables to create a simple HDF5 file.
-
-    There is no need for temporary file cleanup: pytest's `tmp_path` fixture
-    guarantees file system isolation between tests, retains files for later
-    inspection and then removes them in a rolling fashion so that the storage
-    space consumption does not grow indefinitely with the number of test runner
-    invocations.
-    """
+    """Use PyTables to create a simple HDF5 file."""
 
     table_schema = {
         'c0': tables.Time64Col(pos=0),
@@ -36,18 +30,16 @@ def pytables_hdf5_file(tmp_path):
 
     objname = 'pandas_test_timeseries'
 
-    # The `tmp_path` fixture provides a temporary directory unique to the
-    # individual test invocation. Create a file in there.
-    h5path = tmp_path / 'written_with_pytables.h5'
-
-    with tables.open_file(str(h5path), mode='w') as f:
-        t = f.create_table('/', name=objname, description=table_schema)
-        for sample in testsamples:
-            for key, value in sample.items():
-                t.row[key] = value
-            t.row.append()
+    with ensure_clean_path('written_with_pytables.h5') as path:
+        # The `ensure_clean_path` context mgr removes the temp file upon exit.
+        with tables.open_file(path, mode='w') as f:
+            t = f.create_table('/', name=objname, description=table_schema)
+            for sample in testsamples:
+                for key, value in sample.items():
+                    t.row[key] = value
+                t.row.append()
 
-    return h5path, objname, pd.DataFrame(testsamples)
+        yield path, objname, pd.DataFrame(testsamples)
 
 
 class TestReadPyTablesHDF5:

From 60d37e02ab40ab907f517bd5bb16fc7bb2d5c2b0 Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 21 Jun 2019 14:55:01 +0200
Subject: [PATCH 25/26] squash: tests: cleanup

---
 pandas/tests/io/pytables/test_compat.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pandas/tests/io/pytables/test_compat.py b/pandas/tests/io/pytables/test_compat.py
index abe7987c581ba..10c264dddca2c 100644
--- a/pandas/tests/io/pytables/test_compat.py
+++ b/pandas/tests/io/pytables/test_compat.py
@@ -10,7 +10,7 @@
 
 
 @pytest.fixture
-def pytables_hdf5_file(tmp_path):
+def pytables_hdf5_file():
     """Use PyTables to create a simple HDF5 file."""
 
     table_schema = {
@@ -46,6 +46,8 @@ class TestReadPyTablesHDF5:
     """
     A group of tests which covers reading HDF5 files written by plain PyTables
     (not written by pandas).
+
+    Was introduced for regression-testing issue 11188.
     """
 
     def test_read_complete(self, pytables_hdf5_file):

From 1ce1a7005d6d172eb7af9b7bd435da0312fd4dbe Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Fri, 21 Jun 2019 15:33:18 +0200
Subject: [PATCH 26/26] squash: tests: fix isort error

---
 pandas/tests/io/pytables/test_compat.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/pandas/tests/io/pytables/test_compat.py b/pandas/tests/io/pytables/test_compat.py
index 10c264dddca2c..d74e1218ebdb0 100644
--- a/pandas/tests/io/pytables/test_compat.py
+++ b/pandas/tests/io/pytables/test_compat.py
@@ -1,10 +1,8 @@
 import pytest
 
 import pandas as pd
-from pandas.util.testing import assert_frame_equal
-
 from pandas.tests.io.test_pytables import ensure_clean_path
-
+from pandas.util.testing import assert_frame_equal
 
 tables = pytest.importorskip('tables')