Traits 6.2.0

Traits 6.2 is the latest feature release in the Traits 6 series, with several
improvements and fixes over Traits 6.1.

Highlights of this release

• The Traits examples are now distributed as part of the Traits egg, and
  are contributed to the etsdemo application. (The latter can be
  installed from PyPI with pip install etsdemo.)
• Performance of the observe framework has been significantly improved.
• It's no longer necessary to specify a trait comparison mode of
  ComparisonMode.identity when using observe to observe items
  in a List, Dict or Set.
• Support for Python 3.5 has been dropped.
• When importing from Traits, you should always import from one of the api
  modules (for example, traits.api, traits.adaptation.api, etc.) This
  recommendation has now been made explicit in the documentation. If you find
  something you need that's not available from one of the api modules,
  please let the Traits developers know.

Detailed PR-by-PR changes

More than 60 PRs went into this release. The following people contributed to
this release:

• Aaron Ayres
• Alexandre Chabot-Leclerc
• Kit Choi
• Mark Dickinson
• Kevin Duff
• Glen Granzow
• Matt Hancock
• Rahul Poruri
• Eric Prestat
• Kuya Takami
• Hugo van Kemenade
• Aditya Vats
• Corran Webster

Features

• The Property trait type now supports the observe keyword. (#1175,
  #1400)
• Add |= support to TraitDict for Python 3.9 and later. (#1306)
• Add casting keyword to numeric array types. (#547)
• The Traits examples are now part of the Traits package, and so are
  contributed to etsdemo. (#1275)
• The Traits examples package now includes a beginner's tutorial. (#1061)

Performance

• Parsing of the observe string was previously a performance bottleneck.
  This has been fixed, by removing some redundant parsing calls and by caching
  parsing results. (#1343, #1344, #1345)

Changes

• The NoDefaultSpecified constant (used as a default value for
  the TraitType default_value argument) is now public, made
  available from traits.api. (#1384, #1380, #1378)
• The deprecation of the TraitMap trait type has been reversed, because
  there are existing uses of TraitMap that are hard to replace.
  Nevertheless, it is still not recommended to use TraitMap in new code.
  Use Map instead. (#1365)
• An attempt to use PrefixList with an empty list, or PrefixMap or
  Map with an empty dictionary, now raises ValueError. As a result,
  the default default value (which used to be None) is always valid.
  (#1351)
• TraitListEvent arguments are now keyword only. (#1346)
• It's no longer necessary to specify a trait comparison mode of
  ComparisonMode.identity when using observe to observe items
  in a List, Dict or Set. (#1165, #1328, #1240)

Deprecations

• The Function and Method trait types are deprecated. Use
  Callable or Instance instead. (#1399, #1397)
• The edit parameter to configure_traits has been deprecated. (#1311)
• The UnittestTools._catch_warnings function has been deprecated. (#1310)
• The use of the CHECK_INTERFACES global variable for automated
  interface checking has been deprecated. (#1231)

Fixes

• Non-TraitError exceptions raised during Tuple validation are now
  propagated. Previously they were converted into TraitError. (#1393)
• Dynamic Range and Enum traits are now properly validated
  when inside a container (for example Tuple or List). Previously
  no validation was performed. (#1388, #1392)
• Remove the unused module-level constant traits.has_traits.EmptyList.
  (#1366)
• Don't hard-code class names in __repr__ implementations of
  TraitListEvent, TraitSetEvent and TraitDictEvent. (#1335)
• Don't notify on empty update\ s of Dict traits. (#1308)
• Fix exception raised when assigning a NumPy array to a List
  trait. (#1278)
• Fix uses of deprecated logger.warn function. (#1283)
• Fix a bad Instance trait declaration for a private trait in
  the _TraitChangeCollector class. (#1411)

Documentation

• Add "Tutorial" section to the main documentation, based on the
  new traits.examples tutorial content. (#1374)
• Clarify that only the api modules should be used for imports. (#1387)
• Update copyright header end years. (#1376)
• Update contents of image_LICENSE.txt. (#1362)
• Remove mentions of the removed functions adapts and implements from
  the examples and tutorial. (#1367)
• Move Traits introduction description to index.rst. (#1358)
• Fix path to Enthought logo when building docset. (#1285)
• Fix the trait_documenter extension to be less fragile. (#1247)
• Add user manual documentation for the Instance trait type. (#1395)
• Document that the List, Dict and Set trait types copy on
  assignment. (#1402)
• Various other minor improvements, typo fixes, and other documentation fixes.
  (#1396, #1383, #1381, #1384, #1292, #1355, #1350, #1319, #1292, #1401)

Cleanup and other maintenance

• Remove dead code. (#1281)
• Update super usage to the usual Python 3 argument-less pattern. (#1280)
• Remove per-import # noqa comments in api modules in favour of
  per-file ignores in the flake8 configuration. (#1269)
• Remove out-of-date and non-functional coverage badge from README. (#1263)
• Rename _i_observable module to i_observable. (#1296)
• Refactor and simplify method checks. (#1176)
• Fix typo in optional_dependencies comment. (#1235)
• Use ComparisonMode constants instead of magic numbers. (#1229)

Test suite

• Prevent test_enum failures if traitsui or GUI toolkit are not installed.
  (#1349)
• Tests that require pkg_resources are skipped if setuptools is not
  installed. (#1301)
• Fix an order-dependency bug in the test_subclasses_weakref regression
  test. (#1290)
• Fix a typo in a test method name. (#1309)
• Various additional or improved tests for existing code.
  (#1359, #1336, #1330, #1248, #1225, #1208, #1209)

Build and development workflow changes

• Traits now uses GitHub Actions for continuous integration. The Travis CI
  and Appveyor configurations have been removed. (#1296, #1360)
• CI runs are no longer based on EDM. (#878)
• New CI run for the core test suite, without any optional dependencies.
  (#1314)
• Test Python 3.9 in the continuous integration (and drop tests for Python
  3.5 and older). (#1326, #1313, , #1303)
• Make traits.examples into a package. (#1348)
• Make examples directories flake8-clean. (#1353)
• Fix examples packaging nit. (#1363)
• Support -h for getting help in etstool.py. (#1347)
• Add shell command to etstool.py. (#1293)
• Use the flake8_ets package in place of the local copyright_header
  package.
  The copyright_header package has been removed. (#1341)
• Add script check_observe_timing.py to benchmark performance of
  observe to compare with on_trait_change. (#1331)
• Correct the minimum Sphinx version in README. (#1216, #1320)
• Restrict Sphinx version to avoid buggy versions. (#1276)
• Make mypy an optional dependency. (#1289)
• Speed up CI builds for Travis and Appveyor by caching the pip directory
  (now redundant). (#1241)
• Add automated wheel and sdist building for Traits releases. (#1404, #1291)
• Add cron-job workflow to regularly test install of the latest releases
  from PyPI. (#1406)

Traits 6.1.1

Traits 6.1.1 is a bugfix release fixing a handful of minor documentation and
test-related issues with the Traits 6.1.0 release. There are no API-breaking
changes in this release. It's recommended that all users of Traits 6.1.0
upgrade to Traits 6.1.1.

Fixes

• Don't mutate global state at import time in a test module. (#1222)
• Standardize and fix copyright years in source files. (#1227, #1198)
• Fix trait-documenter extension tests for Sphinx 3.1. (#1206)
• Fix trait-documenter extension to handle properties correctly. (#1246)

Documentation fixes

• Expand user manual to mention dispatch. (#1195)
• Fix some spelling and grammar errors in the user manual. (#1210)
• Fix description in README to match the one in the setup script. (#1219)
• Update PyPI links and capitalization in README.rst. (#1250)
• Fix user manual mentioning a nonexisting feature in metadata filter. (#1207)
• Fix typo in comment in optional_dependencies. (#1235)

Traits 6.1.0

Released: 2020-06-05

The Traits library is a foundational component of the Enthought Tool Suite. It
provides observable, typed attributes for Python classes, making those classes
suitable for event-driven dataflow programming and for immediate use as models
for graphical user interfaces, like those provided by the TraitsUI library.

Traits 6.1 is the latest feature release in the Traits 6 series, and contains
several major improvements.

Highlights of this release

• A new observation framework for observing traited
  attributes and other observable objects has been introduced. This is intended
  to provide a full replacement for the existing on_trait_change
  mechanism, and aims to fix a number of fundamental flaws and limitations of
  that mechanism. See the observe-notification section of
  the user manual for an introduction to this framework.

• New TraitList, TraitDict and TraitSet classes have been added,
  subclassing Python's built-in list, dict and
  set (respectively). Instances of these classes are observable
  objects in their own right, and it's possible to attach observers to them
  directly. These classes were primarily introduced to support the new
  observation framework, and are not expected to be used directly. The API for
  these objects and their notification system is provisional, and may change in
  a future Traits release.

• A new Union trait type has been added. This is intended as a
  simpler replacement for the existing Either trait type, which
  will eventually be deprecated.

• New PrefixList, PrefixMap and Map trait types
  have been added. These replace the existing TraitPrefixList,
  TraitPrefixMap and TraitMap subclasses of
  TraitHandler, which are deprecated.

• Typing stubs for the Traits library have been added in a
  traits-stubs package, which will be released separately to PyPI. This
  should help support Traits-using projects that want to make use of type
  annotations and type checkers like mypy.

Notes on upgrading

As far as possible, Traits 6.1 is backwards compatible with Traits 6.0.
However, there are a few things to be aware of when upgrading.

• Traits 6.1 is not compatible with TraitsUI versions older than TraitsUI 7.0.
  A combination of Traits 6.1 or later with TraitsUI 6.x or earlier will fail
  to properly recognise View class variables as
  TraitsUI views, and an error will be raised if you attempt to create a
  TraitsUI view.

• Traits now does no logging configuration at all, leaving all such
  configuration to the application.

  In more detail: trait notification handlers should not raise exceptions in
  normal use, so an exception is logged whenever a trait notification handler
  raises. This part of the behaviour has not changed. What has changed is the
  way that logged exception is handled under default exception handling.

  Previously, Traits added a logging.StreamHandler to the
  top-level "traits" logger, so that trait notification exceptions would
  always be visible. Traits also added a logging.NullHandler to that
  logger. Both of those handlers have now been removed. We now rely on
  Python's "handler of last resort", which will continue to make notification
  exceptions to the user visible in the absence of any application-level
  log configuration.

• When listening for changes to the items of a List trait, an index
  or slice set operation no longer performs an equality check between the
  replaced elements and the replacement elements when deciding whether to issue
  a notification; instead, a notification is always issued if at least one
  element was replaced. For example, consider the following class:

  class Selection(HasTraits):
      indices = List(Int)
  
      @on_trait_change("indices_items")
      def report_change(self, event):
          print("Indices changed: ", event)
  

  When replacing the 8 with the same integer, we get this behavior:

  >>> selection = Selection(indices=[2, 5, 8])
  >>> selection.indices[2] = 8
  Indices changed:  TraitListEvent(index=2, removed=[8], added=[8])
  

  Previously, no notification would have been issued.

• The Color, RGBColor and Font trait factories
  have moved to TraitsUI, and should be imported from there rather than from
  Traits. For backwards compatibility, the factories are still
  available in Traits, but they are deprecated and will eventually
  be removed.

• As a reminder, the Unicode and Long trait types are
  deprecated since Traits 6.0. Please replace uses with Str and
  Int respectively. To avoid excessive noise in Traits-using
  projects, Traits does not yet issue deprecation warnings for existing uses of
  Unicode and Long. Those warnings will be introduced in a
  future Traits release, prior to the removal of these trait types.

Pending deprecations

In addition to the deprecations listed in the changelog below, some parts of
the Traits library are not yet formally deprecated, but are likely to be
deprecated before Traits 7.0. Users should be aware of the following possible
future changes:

• The Either trait type will eventually be deprecated. Where
  possible, use Union instead. When replacing uses of
  Either with Union, note that there are some significant
  API and behavioral differences between the two trait types, particularly with
  respect to handling of defaults. See the user manual for
  more details.

• The trait_modified event trait that's present on all HasTraits
  subclasses will eventually be removed. Users should not rely on it being
  present in an object's class_traits dictionary.

• Trait names starting with trait, traits, _trait or
  _traits may become reserved for use by ETS at some point in the future.
  Avoid using these names for your own traits.

Detailed PR-by-PR changes

More than 160 PRs went into this release. The following people contributed
code changes for this release:

• Ieva Cernyte
• Kit Yan Choi
• Maxime Costalonga
• Mark Dickinson
• Matt Hancock
• Midhun Madhusoodanan
• Shoeb Mohammed
• Franklin Ventura
• Corran Webster

Features

• Add os.PathLike support for Directory traits. (#867)
• Add Union trait type. (#779, #1103, #1107, #1116, #1115)
• Add PrefixList trait type. (#871, #1142, #1144, #1147)
• Add allow_none flag for Callable trait. (#885)
• Add support for type annotation. (#904, #1064)
• Allow mutable values in Constant trait. (#929)
• Add Map and PrefixMap trait types. (#886, #953, #956, #970, #1139,
  #1189)
• Add TraitList as the base list object that can perform validation
  and emit change notifications. (#912, #981, #984, #989, #999, #1003, #1011,
  #1026, #1009, #1040, #1172, #1173)
• Add TraitDict as the base dict object that can perform validation and
  emit change notifications. (#913)
• Add TraitSet as the base set object that can perform validation and
  emit change notifications. (#922, #1043)
• Implement observe to supersede on_trait_change for observing trait
  changes. (#976, #1000, #1007, #1065, #1023, #1066, #1070, #1069, #1067,
  #1080, #1082, #1079, #1071, #1072, #1075, #1085, #1089, #1078, #1093, #1086,
  #1077, #1095, #1102, #1108, #1110, #1112, #1117, #1118, #1123, #1125, #1126,
  #1128, #1129, #1135, #1156)

Changes

• GUI applications using Traits 6.1 will require TraitsUI >= 7.0. (#1134)
• TraitSetEvent and TraitDictEvent initialization arguments are now
  keyword-only. (#1036)
• TraitListObject will no longer skip notifications even if mutations
  result in content that compares equally to the old values. (#1026)
• TraitListEvent.index reported by mutations to a list is now normalized.
  (#1009)
• The default notification error handler for Traits no longer configures
  logging, and the top-level NullHandler log handler has been removed.
  (#1161)

Fixes

• Allow assigning None to CTrait.post_setattr. (#833)
• Fix reference count error. (#907)
• Improve HasTraits introspection with dir(). (#927)
• Fix the datetime-to-str converters used in DatetimeEditor. (#937)
• Raise TraitNotificationError on trailing comma in on_trait_change.
  (#926)
• Fix exception swallowing by Trait attribute access. (#959, #960)
• Allow collections in valid values for Enum trait. (#889)
• Fix TraitError when mutating a list/dict/set inside another container.
  (#1018)
• Fix setting default values via dynamic default methods or overriding trait in
  subclasses for mapped traits, used by Map, Expression, PrefixMap.
  (#1091, #1188)
• Fix setting default values via dynamic default methods or overriding trait in
  subclasses for Expression and AdaptsTo. (#1088, #1119, #1152)

Deprecations

• traits.testing.nose_tools is deprecated. (#880)
• SingletonHasTraits, SingletonHasStrictTraits and
  SingletonHasPrivateTraits are deprecated. (#887)
• TraitMap is deprecated, use Map instead. (#974)
• TraitPrefixMap is deprecated, use PrefixMap instead. (#974)
• TraitPrefixList is deprecated, use PrefixList. (#974)
• Color, RBGColor and Font are now deprecated. Use the ones from
  TraitsUI instead. (#1022)

Removals

• traits_super is removed. (#1015)

Documentation

• Add details on creating custom trait properties. (#387)
• Cross reference special handler signatures for listening to nested attributes
  in list and dict. (#894)
• Replace 'Traits 5' with 'Traits 6' in the documentation. (#903)
• Use major.minor version in documentation. (#1124)
• Add initial documentation on Traits internals. (#958)
• Fix example class OddInt. (#973)
• Add Dos and Donts for writing change handle...

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.