click.core.Option

Options are usually optional values on the command line and have some extra features that arguments don't have. All other parameters are passed onwards to the parameter constructor. :param show_default: Show the default value for this option in its help text. Values are not shown by default, unless :attr:`Context.show_default` is ``True``. If this value is a string, it shows that string in parentheses instead of the actual value. This is particularly useful for dynamic options. For single option boolean flags, the default remains hidden if its value is ``False``. :param show_envvar: Controls if an environment variable should be shown on the help page. Normally, environment variables are not shown. :param prompt: If set to ``True`` or a non empty string then the user will be prompted for input. If set to ``True`` the prompt will be the option name capitalized. :param confirmation_prompt: Prompt a second time to confirm the value if it was prompted for. Can be set to a string instead of ``True`` to customize the message. :param prompt_required: If set to ``False``, the user will be prompted for input only when the option was specified as a flag without a value. :param hide_input: If this is ``True`` then the input on the prompt will be hidden from the user. This is useful for password input. :param is_flag: forces this option to act as a flag. The default is auto detection. :param flag_value: which value should be used for this flag if it's enabled. This is set to a boolean automatically if the option string contains a slash to mark two options. :param multiple: if this is set to `True` then the argument is accepted multiple times and recorded. This is similar to ``nargs`` in how it works but supports arbitrary number of arguments. :param count: this flag makes an option increment an integer. :param allow_from_autoenv: if this is enabled then the value of this parameter will be pulled from an environment variable in case a prefix is defined on the context. :param help: the help string. :param hidden: hide this option from help outputs. .. versionchanged:: 8.1.0 Help text indentation is cleaned here instead of only in the ``@option`` decorator. .. versionchanged:: 8.1.0 The ``show_default`` parameter overrides ``Context.show_default``. .. versionchanged:: 8.1.0 The default of a single option boolean flag is not shown if the default value is ``False``. .. versionchanged:: 8.0.1 ``type`` is detected from ``flag_value`` if given.