Release Traits 6.4.0 · enthought/traits

Traits 6.4 is a minor feature release of Traits, which focuses mainly on typing
stub and documentation updates.

Migrating from Traits 6.3

Traits 6.4 should be largely backwards compatible with Traits 6.3, but there
are a couple of things to watch out for.

Reminder: while the Either and Trait trait types are not yet formally
deprecated, the intention is to eventually deprecate and remove them.
Projects are encouraged to update their code to use Union instead.
Similarly, any uses of the Unicode trait type in your project should
be replaced with Str.
Validation of items within a container (e.g., foos = List(MyTraitType))
now always matches the validation used for the item trait at top level (e.g.,
foo = MyTraitType). Previously, the validation methods used could differ,
thanks to a bug in the container implementations. For most trait types this
will make no difference, but for the Tuple trait type this change has the
consequence that lists will no longer be accepted as valid for Tuple
traits inside list items. See issue #1619 and PR #1625 for more information.
Related to the above: a top-level Tuple() trait declaration currently
accepts Python list objects, while a Tuple declaration with explicit
item types (for example Tuple(Int(), Int())) does not. The support for
list objects in plain Tuple() is deprecated, and will be removed in a
future version of Traits. See PR #1627 for more information.

The following people contributed code changes for this release:

ETSConfig attributes now support deletion. This makes it easier to make
temporary changes to ETSConfig attributes during unit testing. (#1670,
#1686)
Complex trait type validation is now more lenient: any type that
implements __complex__ will be accepted. (#1594)
BaseFloat validation is now more lenient, and matches Float
validation: BaseFloat now also accepts objects whose type has an
__index__ method. (#1595)

An enumerate alias has been removed from traits.trait_base. In the
unlikely event of code that imports enumerate from traits.trait_base,
use the built-in enumerate instead. (#1681)
Fast validation tuples int_fast_validate, float_fast_validate and
complex_fast_validate have been removed from the traits.trait_types
module. (#1601)

TraitListObject, TraitDict object and TraitSetObject now use the
validate method of the appropriate CTrait instances to validate
items, keys and values. Previously the handler's validate method was
used; this gave buggy behaviour in cases where the handler's validate
method differed from the actual validation in use. (#1625)
Fix specification of default_value that incorrectly disregarded
default_value_type. (#1631)
Fix incorrect results from clone_traits applied to List, Dict
and Set traits. (#1624)
The find_resource and store_resource tests are now skipped
if the pkg_resources module is not present in the environment. (#1679)
An ETSConfig test has been renamed so that it's properly picked up
by the test runner. (#1671)
Fix some ETSConfig tests that assume unittest as the test runner. (#1683)
Rename various test-related classes to avoid pytest trying to harvest test
methods from them. (#1684)
Overriding a default for a List or other collection trait in a subclass
now works as expected. Previously, the behaviour was unusably buggy. (#1645)

Tuple traits currently accept Python list objects in some (but
not all) circumstances. That feature is deprecated, and will be removed
in a future version of Traits. (#1627)

Add stubs for Array, ArrayOrNone, and CArray. (#1682)
Fix various stubs for traits.trait_types; add stubs for
traits.ctraits. (#1661)
Fix that TraitError stubs weren't exposed at traits.api level.
(#1658)
Make Int and Float type stubs more accurate. (#1656)
Fix incorrect type stubs for the Dict trait type. (#1655)

Make ETSConfig class documentation visible in the API docs. (#1688)
Add copy buttons to code samples in documentation. (#1651, #1653)
Document Date, Datetime and Time trait types. (#1641)
Fix some missing mentions of Set in notification docs. (#1618)
Document the 'some_trait.-' pattern for on_trait_change. (#1592)
Document that Either should not be used in new code. (#1699)
Document that TraitPrefixMap and TraitPrefixList are deprecated.
(#1702)
Document that the Trait factory function should not be used in new code.
(#1700)
Miscellaneous minor fixes. (#1583, #1611, #1652, #1680)

Don't collect traits-stubs tests under pytest. As a result of this
and other fixes, the test suite now passes under pytest. (#1690)
Update etstool.py for Python 3.8 support. Python 3.8 is now the
default Python version for builds. (#1694)
Use PySide6 for Python >= 3.8 instead of PySide2 in CI testing. (#1685)
Add pyproject.toml files for both Traits and traits-stubs. (#1689, #1676)
Add Python 3.11 to some workflow runs. (#1600, #1660, #1674)
Add Python 3.10 to install-from-PyPI workflow. (#1576)
Allow running the main test workflow manually. (#1607)
Switch Slack channel used to report GitHub Actions failures. (#1650)
Exclude build directory in flake8 configuration. (#1635)
Re-include NumPy as a test dependency on Python 3.10. (#1593)