8.5.0

This is the Click 8.5.0 feature release. A feature release may include new features, remove previously deprecated code, add new deprecation, or introduce potentially breaking changes.

We encourage everyone to upgrade. You can read more about our Version Support Policy on our website.

PyPI: https://pypi.org/project/click/8.5.0/
Changes: https://click.palletsprojects.com/page/changes/#version-8-5-0
Milestone https://github.com/pallets/click/milestone/33

• Add built-in shell completion support for PowerShell (Windows PowerShell
  5.1+ and pwsh 7+) alongside the existing bash, zsh, and fish
  completers. Use _FOO_BAR_COMPLETE=powershell_source foo-bar to generate
  the completion script. #2672 #3637
• Supported versions of Windows enable ANSI terminal styles by default.
  Colorama is no longer a dependency and is not used. #2986 #3505
• {class}Argument accepts a help parameter, and help output includes
  a Positional arguments section when argument help is available. #2983 #3473
• confirm() and prompt() strip ANSI color and style codes from the
  prompt when the output stream does not support them, matching echo().
  This stripping was lost in 8.4.0 when #2969 began writing the
  prompt with input() directly. #3572 #3653
• {class}Path with allow_dash=True no longer triggers a BytesWarning,
  an error under python -bb, when checking a value against the -
  convention. #2877 #3642
• Add {func}custom_version_option, a --version option whose output is
  produced by a callback, covering cases {func}version_option intentionally
  does not. The feature set of {func}version_option is now frozen; see
  discussion #3527. #3581
• style() and secho() no longer silently drop the 256-color index 0
  (black) passed as fg or bg, and now validate color arguments. Invalid
  colors raise a ValueError instead of a TypeError. #3677
• The automatic help option stores its value under the reserved name
  _click_default_help instead of help, so a parameter named help no
  longer breaks parsing. The new name is visible in
  {meth}Command.to_info_dict output. Parameters that overwrite each other's
  value trigger a warning: an argument sharing its name with another
  parameter, or any parameter claiming the reserved name. Options may still
  share a name to compete for the same value (feature switches).
  #2819 #3678
• unstyle and the ANSI handling behind help-text wrapping now strip the full
  CSI escape-sequence grammar. #3681
• Streamline Option flag handling: the flag-kind, type, lazy-default and
  validation steps in Option.__init__ move into focused helpers, and
  flag_value and default keep their unset sentinel at construction
  (resolved lazily on read) so is UNSET reliably tells a user-supplied value
  from an auto-derived one. Runtime behavior is unchanged, but
  {meth}Parameter.to_info_dict now resolves default=True on a feature
  switch to its flag_value, matching what the function receives at call
  time. #3641
• {func}get_binary_stream and {func}get_text_stream are deprecated and
  will be removed in Click 9.0. #3481 #3695
• The following click.utils names were never intentionally public and are
  now private (_-prefixed). The old names remain available with a
  DeprecationWarning until Click 9.0: LazyFile, KeepOpenFile,
  make_default_short_help, PacifyFlushWrapper, and safecall.
  #3099 #3695
• Deprecate {meth}CliRunner.isolated_filesystem. It relies on
  {func}os.chdir, which mutates process-global state and is not
  thread-safe. The helper predates Python 3 and modern pytest: use a
  temporary directory ({class}tempfile.TemporaryDirectory or pytest's
  tmp_path fixture) with absolute paths instead. For running tests in
  parallel, use process-based isolation (such as pytest-xdist) rather
  than threads, since {meth}CliRunner.invoke also redirects the
  process-global standard streams. #3501 #3700 #3704
• prompt() is now generically typed and returns the type produced by
  type, value_proc, or a matching default instead of Any.
  {class}ParamType takes a second optional type parameter describing the
  input value it accepts (ParamType[int, str] for a type converting
  strings to integers), defaulting to Any. #3407
• {meth}Command.get_help_option_names returns the help option names in the
  order they were declared. #3728
• {func}get_pager_file yields a text stream on Windows again. The temporary
  file backend opened its file in binary mode, so writing a str to the pager
  raised TypeError: a bytes-like object is required, not 'str', and the
  color argument was ignored on that path. Regression introduced in 8.4.0
  by #1572. #3731 #3732 #3740 #3739
• {func}progressbar settles on its final position when update_min_steps
  does not divide the total. Steps below that threshold are applied when the
  bar finishes, so show_pos renders 20/20 rather than the last multiple
  it reached. #3571 #3769
• An error raised while writing to the pager no longer gets replaced by
  PermissionError: [WinError 32] on Windows. The temporary file backend
  unlinked its file without closing it first, and Windows refuses to remove a
  file the process still holds open, so the cleanup failure masked the real
  exception. #3731 #3764
• The temporary file the pager writes to on Windows is opened with the encoding
  {func}get_pager_file picked for the output stream, and with
  errors="replace" to match the pipe backend. Any text stdout can encode
  reaches the pager.
• The temporary file pager backend forwards any parameters the user set in
  PAGER to the pager command instead of silently dropping them. On Windows,
  PAGER="less -R" now invokes less -R on the temporary file rather than
  bare less. #3777
• Improve raw mode detection by parsing the option tokens. #3416
  #3777
• {func}edit accepts os.PathLike values for filename, in addition to
  strings. #2869 #3781