Stable

CHANGES.rst

@@ -14,6 +14,8 @@ Unreleased
     :issue:`2705`
 -   Show correct value for flag default when using ``default_map``.
     :issue:`2632`
+-   Fix ``click.echo(color=...)`` passing ``color`` to coloroma so it can be
+    forced on Windows. :issue:`2606`.
 
 
 Version 8.1.7

docs/arguments.rst

@@ -183,6 +183,9 @@ file in the same folder, and upon completion, the file will be moved over to
 the original location.  This is useful if a file regularly read by other
 users is modified.
 
+
+.. _environment-variables:
+
 Environment Variables
 ---------------------
 

docs/documentation.rst

@@ -36,7 +36,7 @@ And what it looks like:
 .. _documenting-arguments:
 
 Documenting Arguments
-~~~~~~~~~~~~~~~~~~~~~
+----------------------
 
 :func:`click.argument` does not take a ``help`` parameter. This is to
 follow the general convention of Unix tools of using arguments for only

docs/index.rst

@@ -68,6 +68,7 @@ usage patterns.
 
    why
    quickstart
+   virtualenv
    setuptools
    parameters
    options

docs/parameters.rst

@@ -3,39 +3,60 @@ Parameters
 
 .. currentmodule:: click
 
-Click supports two types of parameters for scripts: options and arguments.
-There is generally some confusion among authors of command line scripts of
-when to use which, so here is a quick overview of the differences.  As its
-name indicates, an option is optional.  While arguments can be optional
-within reason, they are much more restricted in how optional they can be.
-
-To help you decide between options and arguments, the recommendation is
-to use arguments exclusively for things like going to subcommands or input
-filenames / URLs, and have everything else be an option instead.
-
-Differences
------------
-
-Arguments can do less than options.  The following features are only
-available for options:
-
-*   automatic prompting for missing input
-*   act as flags (boolean or otherwise)
-*   option values can be pulled from environment variables, arguments can not
-*   options are fully documented in the help page, arguments are not
-    (:ref:`this is intentional <documenting-arguments>` as arguments
-    might be too specific to be automatically documented)
-
-On the other hand arguments, unlike options, can accept an arbitrary number
-of arguments.  Options can strictly ever only accept a fixed number of
-arguments (defaults to 1), or they may be specified multiple times using
-:ref:`multiple-options`.
+Click supports only two types  of parameters for scripts (by design): options and arguments.
+
+Options
+----------------
+
+*   Are optional.
+*   Recommended to use for everything except subcommands, urls, or files.
+*   Can take a fixed number of arguments. The default is 1. They may be specified multiple times using :ref:`multiple-options`.
+*   Are fully documented by the help page.
+*   Have automatic prompting for missing input.
+*   Can act as flags (boolean or otherwise).
+*   Can be pulled from environment variables.
+
+Arguments
+----------------
+
+*   Are optional with in reason, but not entirely so.
+*   Recommended to use for subcommands, urls, or files.
+*   Can take an arbitrary number of arguments.
+*   Are not fully documented by the help page since they may be too specific to be automatically documented.  For more see :ref:`documenting-arguments`.
+*   Can be pulled from environment variables but only explicitly named ones. For more see :ref:`environment-variables`.
+
+.. _parameter_names:
+
+Parameter Names
+---------------
+
+Parameters (options and arguments) have a name that will be used as
+the Python argument name when calling the decorated function with
+values.
+
+.. click:example::
+
+    @click.command()
+    @click.argument('filename')
+    @click.option('-t', '--times', type=int)
+    def multi_echo(filename, times):
+        """Print value filename multiple times."""
+        for x in range(times):
+            click.echo(filename)
+
+In the above example the argument's name is ``filename``. The name must match the python arg name. To provide a different name for use in help text, see :ref:`doc-meta-variables`.
+The option's names are ``-t`` and ``--times``. More names are available for options and are covered in :ref:`options`.
+
+And what it looks like when run:
+
+.. click:run::
+
+    invoke(multi_echo, ['--times=3', 'index.txt'], prog_name='multi_echo')
 
 Parameter Types
 ---------------
 
-Parameters can be of different types.  Types can be implemented with
-different behavior and some are supported out of the box:
+The supported parameter types are:
 
 ``str`` / :data:`click.STRING`:
     The default parameter type which indicates unicode strings.
@@ -74,37 +95,10 @@ different behavior and some are supported out of the box:
 .. autoclass:: DateTime
    :noindex:
 
-Custom parameter types can be implemented by subclassing
-:class:`click.ParamType`.  For simple cases, passing a Python function that
-fails with a `ValueError` is also supported, though discouraged.
-
-.. _parameter_names:
-
-Parameter Names
----------------
-
-Parameters (both options and arguments) have a name that will be used as
-the Python argument name when calling the decorated function with
-values.
-
-Arguments take only one positional name. To provide a different name for
-use in help text, see :ref:`doc-meta-variables`.
-
-Options can have many names that may be prefixed with one or two dashes.
-Names with one dash are parsed as short options, names with two are
-parsed as long options. If a name is not prefixed, it is used as the
-Python argument name and not parsed as an option name. Otherwise, the
-first name with a two dash prefix is used, or the first with a one dash
-prefix if there are none with two. The prefix is removed and dashes are
-converted to underscores to get the Python argument name.
-
-
-Implementing Custom Types
--------------------------
+How to Implement Custom Types
+-------------------------------
 
-To implement a custom type, you need to subclass the :class:`ParamType`
-class. Override the :meth:`~ParamType.convert` method to convert the
-value from a string to the correct type.
+To implement a custom type, you need to subclass the :class:`ParamType` class. For simple cases, passing a Python function that fails with a `ValueError` is also supported, though discouraged. Override the :meth:`~ParamType.convert` method to convert the value from a string to the correct type.
 
 The following code implements an integer type that accepts hex and octal
 numbers in addition to normal integers, and converts them into regular

docs/quickstart.rst

@@ -3,98 +3,28 @@ Quickstart
 
 .. currentmodule:: click
 
-You can get the library directly from PyPI::
+Install
+----------------------
+Install from PyPI::
 
     pip install click
 
-The installation into a :ref:`virtualenv` is heavily recommended.
+Installing into a virtual environment is highly recommended. We suggest :ref:`virtualenv-heading`.
 
-.. _virtualenv:
-
-virtualenv
-----------
-
-Virtualenv is probably what you want to use for developing Click
-applications.
-
-What problem does virtualenv solve?  Chances are that you want to use it
-for other projects besides your Click script.  But the more projects you
-have, the more likely it is that you will be working with different
-versions of Python itself, or at least different versions of Python
-libraries.  Let's face it: quite often libraries break backwards
-compatibility, and it's unlikely that any serious application will have
-zero dependencies.  So what do you do if two or more of your projects have
-conflicting dependencies?
-
-Virtualenv to the rescue!  Virtualenv enables multiple side-by-side
-installations of Python, one for each project.  It doesn't actually
-install separate copies of Python, but it does provide a clever way to
-keep different project environments isolated.
-
-Create your project folder, then a virtualenv within it::
-
-    $ mkdir myproject
-    $ cd myproject
-    $ python3 -m venv .venv
-
-Now, whenever you want to work on a project, you only have to activate the
-corresponding environment.  On OS X and Linux, do the following::
-
-    $ . .venv/bin/activate
-    (venv) $
-
-If you are a Windows user, the following command is for you::
-
-    > .venv\scripts\activate
-    (venv) >
-
-Either way, you should now be using your virtualenv (notice how the prompt of
-your shell has changed to show the active environment).
-
-And if you want to stop using the virtualenv, use the following command::
-
-    $ deactivate
-
-After doing this, the prompt of your shell should be as familiar as before.
-
-Now, let's move on. Enter the following command to get Click activated in your
-virtualenv::
-
-    $ pip install click
-
-A few seconds later and you are good to go.
-
-Screencast and Examples
+Examples
 -----------------------
 
-There is a screencast available which shows the basic API of Click and
-how to build simple applications with it.  It also explores how to build
-commands with subcommands.
-
-*   `Building Command Line Applications with Click
-    <https://www.youtube.com/watch?v=kNke39OZ2k0>`_
-
-Examples of Click applications can be found in the documentation as well
-as in the GitHub repository together with readme files:
-
-*   ``inout``: `File input and output
-    <https://github.com/pallets/click/tree/main/examples/inout>`_
-*   ``naval``: `Port of docopt naval example
-    <https://github.com/pallets/click/tree/main/examples/naval>`_
-*   ``aliases``: `Command alias example
-    <https://github.com/pallets/click/tree/main/examples/aliases>`_
-*   ``repo``: `Git-/Mercurial-like command line interface
-    <https://github.com/pallets/click/tree/main/examples/repo>`_
-*   ``complex``: `Complex example with plugin loading
-    <https://github.com/pallets/click/tree/main/examples/complex>`_
-*   ``validation``: `Custom parameter validation example
-    <https://github.com/pallets/click/tree/main/examples/validation>`_
-*   ``colors``: `Color support demo
-    <https://github.com/pallets/click/tree/main/examples/colors>`_
-*   ``termui``: `Terminal UI functions demo
-    <https://github.com/pallets/click/tree/main/examples/termui>`_
-*   ``imagepipe``: `Multi command chaining demo
-    <https://github.com/pallets/click/tree/main/examples/imagepipe>`_
+Some standalone examples of Click applications are packaged with Click. They are available in the `examples folder <https://github.com/pallets/click/tree/main/examples>`_ of the repo.
+
+*   `inout <https://github.com/pallets/click/tree/main/examples/inout>`_ : A very simple example of an application that can read from files and write to files and also accept input from stdin or write to stdout.
+*   `validation <https://github.com/pallets/click/tree/main/examples/validation>`_ : A simple example of an application that performs custom validation of parameters in different ways.
+*   `naval <https://github.com/pallets/click/tree/main/examples/naval>`_ : Port of the `docopt <http://docopt.org/>`_ naval example.
+*   `colors <https://github.com/pallets/click/tree/main/examples/colors>`_ : A simple example that colorizes text. Uses colorama on Windows.
+*   `aliases <https://github.com/pallets/click/tree/main/examples/aliases>`_ : An advanced example that implements :ref:`aliases`.
+*   `imagepipe <https://github.com/pallets/click/tree/main/examples/imagepipe>`_ : A complex example that implements some :ref:`multi-command-chaining` . It chains together image processing instructions. Requires pillow.
+*   `repo <https://github.com/pallets/click/tree/main/examples/repo>`_ : An advanced example that implements a Git-/Mercurial-like command line interface.
+*   `complex <https://github.com/pallets/click/tree/main/examples/complex>`_ : A very advanced example that implements loading subcommands dynamically from a plugin folder.
+*   `termui <https://github.com/pallets/click/tree/main/examples/termui>`_ : A simple example that showcases terminal UI helpers provided by click.
 
 Basic Concepts - Creating a Command
 -----------------------------------

docs/virtualenv.rst

@@ -0,0 +1,54 @@
+.. _virtualenv-heading:
+
+Virtualenv
+=========================
+
+Why Use Virtualenv?
+-------------------------
+
+You should use `Virtualenv <https://virtualenv.pypa.io/en/latest/>`_ because:
+
+*   It allows you to install multiple versions of the same dependency.
+
+*   If you have an operating system version of Python, it prevents you from changing its dependencies and potentially messing up your os.
+
+How to Use Virtualenv
+-----------------------------
+
+Create your project folder, then a virtualenv within it::
+
+    $ mkdir myproject
+    $ cd myproject
+    $ python3 -m venv .venv
+
+Now, whenever you want to work on a project, you only have to activate the
+corresponding environment.
+
+.. tabs::
+
+    .. group-tab:: OSX/Linux
+
+        .. code-block:: text
+
+            $ . .venv/bin/activate
+            (venv) $
+
+    .. group-tab:: Windows
+
+        .. code-block:: text
+
+            > .venv\scripts\activate
+            (venv) >
+
+
+You are now using your virtualenv (notice how the prompt of your shell has changed to show the active environment).
+
+To install packages in the virtual environment::
+
+    $ pip install click
+
+And if you want to stop using the virtualenv, use the following command::
+
+    $ deactivate
+
+After doing this, the prompt of your shell should be as familiar as before.

src/click/__init__.py

@@ -19,6 +19,7 @@
 from .decorators import confirmation_option as confirmation_option
 from .decorators import group as group
 from .decorators import help_option as help_option
+from .decorators import HelpOption as HelpOption
 from .decorators import make_pass_decorator as make_pass_decorator
 from .decorators import option as option
 from .decorators import pass_context as pass_context

src/click/core.py

@@ -1285,25 +1285,19 @@ def get_help_option_names(self, ctx: Context) -> t.List[str]:
         return list(all_names)
 
     def get_help_option(self, ctx: Context) -> t.Optional["Option"]:
-        """Returns the help option object."""
+        """Returns the help option object.
+
+        Unless ``add_help_option`` is ``False``.
+        """
         help_options = self.get_help_option_names(ctx)
 
         if not help_options or not self.add_help_option:
             return None
 
-        def show_help(ctx: Context, param: "Parameter", value: str) -> None:
-            if value and not ctx.resilient_parsing:
-                echo(ctx.get_help(), color=ctx.color)
-                ctx.exit()
-
-        return Option(
-            help_options,
-            is_flag=True,
-            is_eager=True,
-            expose_value=False,
-            callback=show_help,
-            help=_("Show this message and exit."),
-        )
+        # Avoid circular import.
+        from .decorators import HelpOption
+
+        return HelpOption(help_options)
 
     def make_parser(self, ctx: Context) -> OptionParser:
         """Creates the underlying option parser for this command."""
@@ -2671,7 +2665,9 @@ def _parse_decls(
         if name is None:
             if not expose_value:
                 return None, opts, secondary_opts
-            raise TypeError("Could not determine name for option")
+            raise TypeError(
+                f"Could not determine name for option with declarations {decls!r}"
+            )
 
         if not opts and not secondary_opts:
             raise TypeError(
@@ -3011,7 +3007,7 @@ def _parse_decls(
         if not decls:
             if not expose_value:
                 return None, [], []
-            raise TypeError("Could not determine name for argument")
+            raise TypeError("Argument is marked as exposed, but does not have a name.")
         if len(decls) == 1:
             name = arg = decls[0]
             name = name.replace("-", "_").lower()