Fix ValueError when reading a Dataframe with HDFStore in Python 3 fro… (#24510)

Author: faulaire

doc/source/whatsnew/v0.24.0.rst

@@ -1519,7 +1519,6 @@ MultiIndex
 I/O
 ^^^
 
-
 .. _whatsnew_0240.bug_fixes.nan_with_str_dtype:
 
 Proper handling of `np.NaN` in a string data-typed column with the Python engine
@@ -1591,6 +1590,7 @@ Notice how we now instead output ``np.nan`` itself instead of a stringified form
 - Bug in :func:`pandas.io.json.json_normalize` that caused it to raise ``TypeError`` when two consecutive elements of ``record_path`` are dicts (:issue:`22706`)
 - Bug in :meth:`DataFrame.to_stata`, :class:`pandas.io.stata.StataWriter` and :class:`pandas.io.stata.StataWriter117` where a exception would leave a partially written and invalid dta file (:issue:`23573`)
 - Bug in :meth:`DataFrame.to_stata` and :class:`pandas.io.stata.StataWriter117` that produced invalid files when using strLs with non-ASCII characters (:issue:`23573`)
+- Bug in :class:`HDFStore` that caused it to raise ``ValueError`` when reading a Dataframe in Python 3 from fixed format written in Python 2 (:issue:`24510`)
 
 Plotting
 ^^^^^^^^

pandas/io/pytables.py

@@ -2501,7 +2501,7 @@ def set_attrs(self):
     def get_attrs(self):
         """ retrieve our attributes """
         self.encoding = _ensure_encoding(getattr(self.attrs, 'encoding', None))
-        self.errors = getattr(self.attrs, 'errors', 'strict')
+        self.errors = _ensure_decoded(getattr(self.attrs, 'errors', 'strict'))
         for n in self.attributes:
             setattr(self, n, _ensure_decoded(getattr(self.attrs, n, None)))
 
@@ -2661,6 +2661,7 @@ def read_index_node(self, node, start=None, stop=None):
 
         if 'name' in node._v_attrs:
             name = _ensure_str(node._v_attrs.name)
+            name = _ensure_decoded(name)
 
         index_class = self._alias_to_class(_ensure_decoded(
             getattr(node._v_attrs, 'index_class', '')))

pandas/tests/io/data/legacy_hdf/legacy_table_fixed_py2.h5

@@ -4540,6 +4540,20 @@ def test_pytables_native2_read(self, datapath):
             d1 = store['detector']
             assert isinstance(d1, DataFrame)
 
+    def test_legacy_table_fixed_format_read_py2(self, datapath):
+        # GH 24510
+        # legacy table with fixed format written en Python 2
+        with ensure_clean_store(
+                datapath('io', 'data', 'legacy_hdf',
+                         'legacy_table_fixed_py2.h5'),
+                mode='r') as store:
+            result = store.select('df')
+            expected = pd.DataFrame([[1, 2, 3, 'D']],
+                                    columns=['A', 'B', 'C', 'D'],
+                                    index=pd.Index(['ABC'],
+                                                   name='INDEX_NAME'))
+            assert_frame_equal(expected, result)
+
     def test_legacy_table_read(self, datapath):
         # legacy table types
         with ensure_clean_store(