Traits 6.0.0

This is the final release for Traits 6.0.0. There were no changes (apart from the version number change) between the 6.0.0rc0 release candidate and the final release. See the 6.0.0rc0 release notes for the full list of changes since 5.2.0.

About Traits 6.0

Traits 6.0 is a major update to the Traits package, with a number of
backward incompatible changes from its predecessor. Notable changes:

• Python 2.7 is no longer supported; Traits 6.0 requires Python 3.5 or later.
• Trait types related to Python 2 (for example Unicode and Long) have
  been deprecated in favour of their Python 3 equivalents (for example Str
  and Int).
• Many little-used historical features of Traits have been deprecated, and
  are scheduled for removal in Traits 7.0.
• Some historical features of Traits that had no evidence of external usage
  were removed in Traits 6.0.
• Introspection of CTrait and HasTraits objects is greatly improved.
  All of the internal state that was previously hidden within the C extension
  is now accessible from Python.
• The Traits codebase has undergone some significant reorganizations,
  reformattings and style cleanups to make it easier to work with, and
  to improve the separation between Traits and TraitsUI.
• This release was focused mainly on cleanup and bugfixing. Nevertheless,
  it contains a sprinkling of new features. There's a new Datetime
  trait type. The Enum trait type now supports Python enumerations.
  The File trait type supports path-like objects.

More than 150 PRs went into this release. The following people contributed
code changes for this release:

• Kit Yan Choi
• Mark Dickinson
• Kevin Duff
• Robert Kern
• Midhun Madhusoodanan
• Shoeb Mohammed
• Sai Rahul Poruri
• Corran Webster
• John Wiggins

First release candidate for Traits 6.0.0

Release notes

Traits 6.0 is a major update to the Traits package, with a number of
backward incompatible changes from its predecessor. Notable changes:

• Python 2.7 is no longer supported; Traits 6.0 requires Python 3.5 or later.
• Trait types related to Python 2 (for example Unicode and Long) have
  been deprecated in favour of their Python 3 equivalents (for example Str
  and Int).
• Many little-used historical features of Traits have been deprecated, and
  are scheduled for removal in Traits 7.0.
• Some historical features of Traits that had no evidence of external usage
  were removed in Traits 6.0.
• Introspection of CTrait and HasTraits objects is greatly improved.
  All of the internal state that was previously hidden within the C extension
  is now accessible from Python.
• The Traits codebase has undergone some significant reorganizations,
  reformattings and style cleanups to make it easier to work with, and
  to improve the separation between Traits and TraitsUI.
• This release was focused mainly on cleanup and bugfixing. Nevertheless,
  it contains a sprinkling of new features. There's a new Datetime
  trait type. The Enum trait type now supports Python enumerations.
  The File trait type supports path-like objects.

More than 150 PRs went into this release. The following people contributed
code changes for this release:

• Kit Yan Choi
• Mark Dickinson
• Kevin Duff
• Robert Kern
• Midhun Madhusoodanan
• Shoeb Mohammed
• Sai Rahul Poruri
• Corran Webster
• John Wiggins

Porting guide

For the most part, existing code that works with Traits 5.2.0 should
continue to work with Traits 6.0.0 without changes. However, there
are some potentially breaking changes in Traits 6.0.0, and we recommend
applying caution when upgrading.

Here's a guide to dealing with some of the potentially breaking changes.

• The Unicode and CUnicode trait types are now simply synonyms for
  Str and CStr. Unicode and CUnicode are considered deprecated.
  For now, no deprecation warning is issued on use of these deprecated trait
  types, but in Traits 6.1.0 and later, warnings may be issued, and in Traits
  7.0.0 these trait types may be removed. It's recommended that users update
  all uses of Unicode to Str and CUnicode to CStr to avoid
  warnings or errors in the future.

• Similarly, Long and CLong are now synonyms for Int and CInt.
  The same recommendations apply as for the Unicode / Str trait types.

• Uses of NO_COMPARE, OBJECT_IDENTITY_COMPARE and RICH_COMPARE
  should be replaced with the appropriate ComparisonMode enumeration
  members.

• The validation for a Instance(ISomeInterface) trait type has changed,
  where ISomeInterface is a subclass of Interface. Previously, an
  assignment to such a trait validated the type of the assigned value against
  the interface, method by method. Now an isinstance check is performed
  against the interface instead. Make sure that classes implementing a given
  interface have the appropriate provides decorator.

  One notable side-effect of the above change is that plain mock.Mock
  instances can no longer be assigned to Instance(ISomeInterface) traits.
  To get around this, use spec=ISomeInterface when creating your mock
  object.

  This change does not affect Instance traits for non-interface classes.

• The format of TraitListEvents has changed: for list events generated from
  a slice set or slice delete operation where that slice had a step other
  than 1, the added and removed fields of the event had an extra
  level of list wrapping (for example, added might be [[1, 2, 3]]
  instead of [1, 2, 3]). In Traits 6.0, this extra wrapping has been
  removed. There may be existing code that special-cased the extra wrapping.

• Many classes and functions have moved around within the Traits codebase.
  If you have code that imports directly from Traits modules and subpackages
  instead of from traits.api or the other subpackage api modules, some
  of those imports may fail. To avoid potential for ImportErrors, you
  should import from traits.api whenever possible. If you find yourself
  needing some piece of Traits functionality that isn't exposed in
  traits.api, and you think it should be, please open an issue on the
  Traits bug tracker.

Features

• Add new Datetime trait type. (#737, #814, #813, #815, #848)

• Support Python Enums as value sets for the Enum trait. (#685, #828, #855)

• Add Subclass alias for the Type trait type. (#739)

• Add path-like support for the File trait. (#736)

• Add new ComparisonMode enumeration type to replace the old
  NO_COMPARE, OBJECT_IDENTITY_COMPARE and RICH_COMPARE
  constants. The old constants are deprecated. (#830, #719, #680)

• Add fast validation for Callable trait type; introduce
  new BaseCallable trait type for subclassing purposes.
  (#798, #795, #767)

• Add CTrait.comparison_mode property to allow inspection and
  modification of a trait's comparison mode. (#758, #735)

• Add as_ctrait converter function to traits.api. This function
  converts a trait-like object or type to a CTrait, raising TypeError
  for objects that can't be interpreted as a CTrait. It's intended
  for use by users who want to create their own parameterised trait
  types.

  The as_ctrait feature comes with, and relies upon, a new informal
  interface: objects that can be converted to something of type CTrait can
  provide an zero-argument as_ctrait method that returns a new CTrait.
  Types can provide an instantiate_and_get_ctrait method, which when
  called with no arguments provides a new CTrait for that type.
  (#783, #794)

• Add a new HasTraits._class_traits method for introspection of an
  object's class traits. This parallels the existing
  HasTraits._instance_traits method. This method is intended for use in
  debugging. It's not recommended for users to modify the returned dictionary.
  (#702)

• Add CTrait.set_default_value method for setting information about the
  default of a CTrait. This provides an alternative to the previous method
  of using CTrait.default_value. The use of CTrait.default_value to set
  (rather than get) default information is deprecated. (#620)

• Add new methods HasTraits._trait_notifications_enabled,
  HasTraits._trait_notifications_vetoed to allow introspection of the
  notifications states set by the existing methods
  HasTraits._trait_change_notify and HasTraits._trait_veto_notify.
  (#704)

• Add TraitKind, ValidateTrait and DefaultValue Python enumeration
  types to replace previous uses of magic integers within the Traits codebase.
  (#680, #857)

• The various CTrait internal flags are now exposed to Python as
  properties: CTrait.is_property (read-only), CTrait.modify_delegate,
  CTrait.setattr_original_value, CTrait.post_setattr_original_value,
  CTrait.is_mapped, and CTrait.comparison_mode. (#666, #693)

Changes

• When pickling a CTrait, the py_post_setattr and py_validate
  fields are pickled directly. Previously, callables for those fields were
  replaced with a -1 sentinel on pickling. (#780)
• A TraitListEvent is no longer emitted for a slice deletion which
  doesn't change the contents of the list. (For example, del obj.mylist[2:]
  on a list that only has 2 elements.) (#740)
• The added and removed attributes on a TraitListEvent are now
  always lists containing the added or removed elements. Previously, those
  lists were nested inside another list in some cases. (#771)
• Change Instance(ISomeInterface) to use an isinstance check on
  trait set instead of using the dynamic interface checker. (#630)
• Create an new AbstractViewElement abstract base class, and register
  the TraitsUI ViewElement as implementing it. This paves the way for
  removal of Traits UI imports from Traits. (#617)
• ViewElements are now computed lazily, instead of at HasTraits
  subclass creation time. This removes a traitsui import from
  the trait.has_traits module. (#614)
• The traits.util.clean_filename utility now uses a different algorithm,
  and should do a better job with accented and Unicode text. (#589)
• Floating-point and integer checks are now more consistent between classes.
  In particular, BaseInt validation now matches Int validation, and
  Range type checks now match those used in Int and Float. (#588)
• An exception other than TraitError raised during validation of a
  compound trait will now be propagated. Previously, that exception would
  be swallowed. (#581)
• Traits no longer has a runtime dependency on the six package. (#638)
• Use pickle protocol 3 instead of pickle protocol 1 when writing pickled
  object state to a file in configure_traits. (#796)
• In traits.testing.optional_dependencies, make sure traitsui.api is
  available whenever traitsui is. (#616)
• TraitInstance now inherits directly from TraitHandler instead of
  (the now removed) ThisClass. (#761)

Fixes

• Fix a use of the unsupported ValidateTrait.int_range. (#805)
• Remove unnecessary copy method override from TraitSetObject. (#759)
• Fix TraitListObject.clear to issue the appropriate items event. (#732)
• Fix confusing error message when [None] passed into
  List(This(allow_none=False)). (#734)
• Fix name-mangling of double-underscore private methods in classes whose
  name begins with an underscore. (#724)
• Fix bytes_editor and ``passw...

Traits version 5.2.0

This is a minor feature release, with various small updates and bugfixes.

The most notable user-facing changes are the deprecation of the Category class, which is scheduled for removal in Traits 6.0.0, and the removal of the Class, ListClass and ListInstance Trait types, which relate to old-style Python 2 classes.

Summary of changes since the 5.1.2 release:

Enhancements

• Support installation from source archives. (#528)

Fixes

• Ensure TraitListEvent.index is always an integer. (#548)
• Update the deprecated collections.MutableMapping import. (#530)
• Fix inadvertent modification of the Category base class. (#509)
• Rework version handling in setup.py. (#515)
• Don't autogenerate documentation for ViewElement. (#559)
• Ensure that all tests are unittest compatible. (#551)

Changes

• Replace occurences of deprecated AdaptsTo with Supports. (#532)
• Remove Class trait. (#520)
• Deprecate Category trait. (#510)
• Fix typos in docstrings. (#502)
• Use decorator form of classmethod. (#500)
• Remove redefinition of NullHandler. (#518)
• Add an import check helper. (#521)
• Clean up Cython tests. (#555)
• Clean up test output. (#553)

Miscellaneous

• Update EDM version on CI to version 2.0.0. (#560)
• Don't finish fast on CI. (#556)
• Use unittest to run tests in CI. (#552)
• Low-level fixes and style cleanup in etstool.py. (#550)
• Add --editable option for install, update CI commands. (#546)
• Make git commit hash available to archives. (#526)
• Fix use of non-edm envs as bootstrap envs on Windows. (#512)
• Remove edm installed package before installing from source. (#516)
• Add help text to click options. (#514)
• Various cleanups, fixes and enhancements in etstool.py. (#511)

Traits version 5.1.2

This is a bugfix release that fixes an issue with the traits-documenter Sphinx extension. This issue produced invalid reST from Traits with multiline definitions, and could prevent PDF documentation builds from completing successfully.

Fixes

• Traits documenter no longer generates bad reST for traits whose definition
  spans multiple source lines. (#494)

Traits version 5.1.1

This is a bugfix release, fixing a regression in Traits 5.1.0 that prevented Traits UI applications working correctly on Python 2.7. (The bug does not affect Python 3.)

Released: 2019-04-18

Fixes

• Revert a change (#449) which accidentally broke external uses of
  _py2to3.str_find and _py2to3.str_rfind. (#472)

Traits version 5.1.0

Summary

This release reverts a feature introduced into the 5.0.0 release, namely pickleability and deep copying of dynamically added traits (traits added via the add_trait method). That feature unfortunately introduced some unexpected breakage, so has had to be reverted for the time being.

The release also includes various other minor features and fixes.

Enhancements

• Make UUID trait initializable. (#459)
• Change default FileEditor behavior for a File trait based on
  whether exists=True is specified for that trait. (#451, #467)

Changes

• The changes made in #373 to make dynamically-added traits pickleable have
  been reverted. (#462)
• traits.api.python_version has been removed. Internals have been
  refactored to use six.PY2 in preference to sys.version_info.
  (#449)
• Don't depend on the 3rd party mock library on Python 3; use
  unittest.mock instead. (#446)

Fixes

• Fix a fragile NumPy-related test that failed (RuntimeError: empty_like method already has a docstring) with the newest version of NumPy.
  (#443)

Miscellaneous

• traits._version.git_revision now gives the full commit hash (for local
  builds) instead of an abbreviated 7 hex-digit version. (#453)
• Fix copyright years in documentation build. (#445)
• Rename README.txt to README.rst, so that GitHub renders it nicely.
• Code cleanups: remove "EOF" markers from code. Remove __main__ blocks
  for unit tests. Remove imports of unittest from unittest_tools.
  (#448, #446)
• Update Travis CI and Appveyor configurations to run tests against
  all PR branches, not just PRs against master. (#466)

5.0.0 release of Traits

This major release accumulates more than an year's worth of improvements,
changes and bug fixes to the code base.

A few highlights of this release are :

• Removal of 2to3 fixers and the use of six to provide Python 2/3 compatibility
• Removal of deprecated traits.protocols submodule and related utils.
• New HasRequiredTraits class
• Better IPython tab completion for HasTraits subclasses

See the changelog for the complete list of changes included in this release.

Traits 4.6.0

This is an incremental release over 4.5, accumulating over a year's worth of
bugfixes and small improvements to the code.

Highlights of this release include:

• support for Python 3.4 and 3.5.
• new Bytes and ValidatedTuple traits.
• a new ArrayOrNone trait which correctly handles None comparisons with Numpy
  arrays.
• clean-up of the ETSConfig code for TraitsUI toolkit selection.
• better compatibility with NumPy scalar types.
• many other bugfixes and improvements.