Eliminate compatibility mode from HDF5 I/O

CHANGES.rst

@@ -37,6 +37,8 @@ astropy.io.ascii
 astropy.io.misc
 ^^^^^^^^^^^^^^^
 
+- Eliminate deprecated compatibility mode when writing ``Table`` metadata to HDF5 format. [#8899]
+
 astropy.io.fits
 ^^^^^^^^^^^^^^^
 

astropy/io/misc/hdf5.py

@@ -222,8 +222,7 @@ def _encode_mixins(tbl):
 
 
 def write_table_hdf5(table, output, path=None, compression=False,
-                     append=False, overwrite=False, serialize_meta=False,
-                     compatibility_mode=False):
+                     append=False, overwrite=False, serialize_meta=False):
     """
     Write a Table object to an HDF5 file
 
@@ -304,8 +303,7 @@ def write_table_hdf5(table, output, path=None, compression=False,
             return write_table_hdf5(table, f, path=path,
                                     compression=compression, append=append,
                                     overwrite=overwrite,
-                                    serialize_meta=serialize_meta,
-                                    compatibility_mode=compatibility_mode)
+                                    serialize_meta=serialize_meta)
         finally:
             f.close()
 
@@ -357,19 +355,8 @@ def write_table_hdf5(table, output, path=None, compression=False,
         header_yaml = meta.get_yaml_from_table(table)
 
         header_encoded = [h.encode('utf-8') for h in header_yaml]
-        if compatibility_mode:
-            warnings.warn("compatibility mode for writing is deprecated",
-                          AstropyDeprecationWarning)
-            try:
-                dset.attrs[META_KEY] = header_encoded
-            except Exception as e:
-                warnings.warn(
-                "Attributes could not be written to the output HDF5 "
-                "file: {0}".format(e))
-
-        else:
-            output_group.create_dataset(meta_path(name),
-                                        data=header_encoded)
+        output_group.create_dataset(meta_path(name),
+                                    data=header_encoded)
 
     else:
         # Write the Table meta dict key:value pairs to the file as HDF5

astropy/io/misc/tests/test_hdf5.py

@@ -14,6 +14,7 @@
 from astropy.time import Time, TimeDelta
 from astropy.units.quantity import QuantityInfo
 from astropy.utils.exceptions import AstropyUserWarning
+from astropy.utils.data import get_pkg_data_filename
 
 try:
     import h5py
@@ -456,8 +457,12 @@ def test_preserve_serialized(tmpdir):
 
 
 @pytest.mark.skipif('not HAS_H5PY or not HAS_YAML')
-def test_preserve_serialized_compatibility_mode(tmpdir):
-    test_file = str(tmpdir.join('test.hdf5'))
+def test_preserve_serialized_old_meta_format(tmpdir):
+    """Test the old meta format
+
+    Only for some files created prior to v4.0, in compatibility mode.
+    """
+    test_file = get_pkg_data_filename('data/old_meta_example.hdf5')
 
     t1 = Table()
     t1['a'] = Column(data=[1, 2, 3], unit="s")
@@ -468,13 +473,6 @@ def test_preserve_serialized_compatibility_mode(tmpdir):
     t1.meta['b'] = 1
     t1.meta['c'] = {"c0": [0, 1]}
 
-    with catch_warnings() as w:
-        t1.write(test_file, path='the_table', serialize_meta=True,
-                 overwrite=True, compatibility_mode=True)
-
-    assert str(w[0].message).startswith(
-        "compatibility mode for writing is deprecated")
-
     t2 = Table.read(test_file, path='the_table')
 
     assert t1['a'].unit == t2['a'].unit
@@ -536,25 +534,6 @@ def test_metadata_very_large(tmpdir):
     assert t1.meta == t2.meta
 
 
-@pytest.mark.skipif('not HAS_H5PY or not HAS_YAML')
-def test_metadata_very_large_fails_compatibility_mode(tmpdir):
-    """Test that very large metadata do not work in compatibility mode."""
-    test_file = str(tmpdir.join('test.hdf5'))
-    t1 = Table()
-    t1['a'] = Column(data=[1, 2, 3])
-    t1.meta["meta"] = "0" * (2 ** 16 + 1)
-    with catch_warnings() as w:
-        t1.write(test_file, path='the_table', serialize_meta=True,
-                 overwrite=True, compatibility_mode=True)
-    assert len(w) == 2
-
-    # Error message slightly changed in h5py 2.7.1, thus the 2part assert
-    assert str(w[1].message).startswith(
-        "Attributes could not be written to the output HDF5 "
-        "file: Unable to create attribute ")
-    assert "bject header message is too large" in str(w[1].message)
-
-
 @pytest.mark.skipif('not HAS_H5PY')
 def test_skip_meta(tmpdir):