Display regular line breaks in help

[amotl]

Hi there,

first things first: Thanks Armin, David, and the whole community for conceiving and maintaining the excellent Click toolkit.

It feels like we have been looking for a solution to display help text from a Python docstring verbatim for a long time, and apparently missed to discover the documentation about preventing rewrapping, and GH-56.

The suggestion to use the \b escape marker saved our day, so we generalized the idea at earthobservations/wetterdienst@c086fc1e4f3:

import textwrap

def docstring_format_verbatim(text: str) -> str:
    """
    Format docstring to be displayed verbatim as a help text by Click.

    - https://click.palletsprojects.com/en/8.1.x/documentation/#preventing-rewrapping
    - https://github.com/pallets/click/issues/56
    """
    text = textwrap.dedent(text)
    lines = []
    for line in text.splitlines():
        is_empty_line = line.strip() == ""
        if is_empty_line:
            lines.append("\b")
        else:
            lines.append(line)
    return "\n".join(lines)

To be used like:

@click.group("acme", help=docstring_format_verbatim(acme_help.__doc__))

We hope this recipe helps others who are in the same situation. Please let us know if we missed any feature already available within Click, which would make this workaround obsolete. Thank you again!

With kind regards,
Andreas.