A solution to the lack of UI for Dash's user docsets in Zeal. Uses Python 3 and easygui (pip3 install easygui)

download_zeal_user_docsets.py

"""Download Dash User Docsets and install them in Zeal"""
import configparser
import json
import tarfile
import urllib.request
from pathlib import Path
from sys import platform

import easygui

USER_DOCSETS_URL = "https://dashes-to-dashes.herokuapp.com/docsets/contrib"
APP_TITLE = "Download Zeal user docsets"
ZEAL_NIX_CONFIG_PATH = Path.home() / ".config" / "Zeal" / "Zeal.conf"
ZEAL_WIN_DOCSETS_DIR = Path.home() / "AppData" / "Local" / "Zeal" / "Zeal" / "docsets"


def get_zeal_docsets_dir() -> Path:
    if platform == "win32":
        assert ZEAL_WIN_DOCSETS_DIR.is_dir()
        return ZEAL_WIN_DOCSETS_DIR
    else:
        config = configparser.ConfigParser()
        config.read([ZEAL_NIX_CONFIG_PATH.resolve()])
        docsets_dir = Path(config["docsets"]["path"])
        assert docsets_dir.is_dir()
        return docsets_dir


def fetch_and_parse_json(url: str) -> dict:
    response = urllib.request.urlopen(url)
    data = response.read()
    text = data.decode("utf-8")
    return json.loads(text)


def choose_docsets(user_docsets: list) -> list:
    msg = "Select all the user docsets you want to install."
    return easygui.multchoicebox(msg, APP_TITLE, [d["name"] for d in user_docsets])


def download_and_extract_docsets(urls: list, directory: str):
    for url in urls:
        easygui.msgbox(
            f"Downloading {url} and extracting it in {directory}.\n\n"
            "Please press OK and wait.",
            APP_TITLE,
        )
        with urllib.request.urlopen(url) as response:
            try:
                with tarfile.open(fileobj=response, mode="r:gz") as tar:
                    tar.extractall(directory)
            except OSError as exception:
                show_exception(exception)


def search_url(choices: list, user_docsets: list) -> list:
    return [d["archive"] for d in user_docsets if d["name"] in choices]


def confirm_docset_download(choices: list) -> bool:
    return easygui.ccbox(
        f"Docsets {', '.join(choices)} will now be installed", APP_TITLE,
    )


def download_more_docsets() -> bool:
    return easygui.ynbox(
        "Do you want to install more docsets?", APP_TITLE, ("Yes", "No")
    )


def exit_message():
    easygui.msgbox(
        "Bye bye.\n\nPlease remember to restart Zeal to refresh the docsets.",
        APP_TITLE,
        "Quit",
    )


def get_existing_docsets(docsets_dir: Path) -> list:
    return [x.stem.lower() for x in docsets_dir.iterdir() if x.is_dir()]


def filter_existing_docsets(user_docsets: list, existing_docsets: list) -> list:
    return [
        x
        for x in user_docsets
        if Path(x["archive"]).stem.lower() not in existing_docsets
    ]


def show_exception(exception: Exception):
    easygui.exceptionbox(f"!!! Error: {exception}", APP_TITLE)


if __name__ == "__main__":
    try:
        docsets_dir = get_zeal_docsets_dir()
        print(f"Downloading the docset list from {USER_DOCSETS_URL}...")
        user_docsets = fetch_and_parse_json(USER_DOCSETS_URL)
        while True:
            existing_docsets = get_existing_docsets(docsets_dir)
            user_docsets = filter_existing_docsets(user_docsets, existing_docsets)
            user_docsets = sorted(user_docsets, key=lambda x: x["name"].casefold())
            choices = choose_docsets(user_docsets)
            if not choices:
                break
            docset_urls = search_url(choices, user_docsets)
            if confirm_docset_download(choices):
                download_and_extract_docsets(docset_urls, docsets_dir)
            if not download_more_docsets():
                break
        exit_message()
    except Exception as exception:
        show_exception(exception)

(you might need sudo apt-get install python3-pip python3-tk)

Error: list index out of range

Error: list index out of range

Apparently user can multi-choice so choice (line #68) is a list. This works for me: https://gist.github.com/scrool/0186ece9cfe369eb6c1c0e64a2a6ff4f

@D1mon @scrool fixed in the latest version!

On top of that, the latest version works for Windows, and can download multiple docsets in one session.