PyWry Web Viewer

Easily create HTML webviewers in python utilizing the wry library. Unlike many HTML viewers that exist for Python - Pywry allows you to run javacsript. PyWry is also a ~2mb footprint for Mac and Windows - Linux will require a few more libraries which are listed below.

Please note: this library is currently in early alpha and is NOT ready for production use.

Installation

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PyWry is available on PyPI and can be installed with pip:

pip install pywry-nightly

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For development, you can install from source with the following steps:

• Clone the repository: git clone https://github.com/OpenBB-finance/pywry.git
• Install rust: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
• Create a virtual environment: python -m venv venv
• Acitvate the environment: source venv/bin/activate (Unix) or venv\Scripts\activate (Windows)
• Install dependencies: pip install .[dev]
• Build the pip package: maturin build
• Install the package: pip install [file path from above] --force-reinstall

Usage

import asyncio
import sys

from pywry import PyWry


async def main_loop():
    while True:
        await asyncio.sleep(1)


if __name__ == "__main__":
    try:
        handler = PyWry()
        handler.send_html("<h1 style='color: red;'>Welcome to PyWry!</h1>")
        handler.start()

        # PyWry creates a new thread for the backend,
        # so we need to run the main loop in the main thread.
        # otherwise, the program will exit immediately.
        handler.loop.run_until_complete(main_loop())
    except KeyboardInterrupt:
        print("Keyboard interrupt detected. Exiting...")
        sys.exit(0)

JSON Keys

PyWry uses a JSON object to communicate between the python and rust backends and the javascript frontend. The following keys are available:

Key	Type	Description
html	Path | str	The path to the HTML file to be loaded, or HTML string.
title	str	The title of the window.
icon	str | Path	The path to png icon to be used for the window.
json_data	str | dict	A JSON string or dictionary to be passed to the javascript frontend. (see below)
height	int	The height of the window.
width	int	The width of the window.
download_path	str | Path	The path to the download directory.

Javascript

PyWry allows you to run javascript in the frontend. To do this, you can pass a dictionary of data to the json_data key in the send_html method. This dictionary will be converted to a JSON string and passed to the frontend. You can then access this data in the frontend by using the window.json_data object. For example:

---

Python

from pathlib import Path
# code from above ...

# change send_html line to:
        handler.send_html(
            html=Path(__file__).parent / "index.html", json_data={"name": "PyWry"}
        )

---

HTML

<html>
    <head>
        <script>
            window.onload = () => {
                // if you passed a JSON string, you will need to parse it first
                if (typeof window.json_data === "string") {
                    window.json_data = JSON.parse(window.json_data);
                }
                document.getElementById("name").innerHTML = window.json_data.name;
            };
        </script>
    </head>
    <body>
        <h1 style='color: red;'>Hello, <span id="name"></span>!</h1>
    </body>
</html>

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Platform-specific notes

All platforms use TAO to build the window, and wry re-exports it as an application module. Here is the underlying web engine each platform uses, and some dependencies you might need to install.

Linux

Tao uses gtk-rs and its related libraries for window creation and wry also needs WebKitGTK for WebView. So please make sure the following packages are installed:

Arch Linux / Manjaro

sudo pacman -S webkit2gtk

Debian / Ubuntu

sudo apt install libwebkit2gtk-4.0-dev

Fedora / CentOS / AlmaLinux

sudo dnf install gtk3-devel webkit2gtk3-devel

macOS

WebKit is native to macOS, so no additional dependencies are needed.

Windows

WebView2 provided by Microsoft Edge Chromium is used. So wry supports Windows 7, 8, 10 and 11.

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Troubleshooting Linux

"/lib/x86_64-linux-gnu/libgio-2.0.so.0: undefined symbol: g_module_open_full"

This is a known issue with the gio library. You can fix it by installing the libglib2.0-dev package.

PyWry is a project that aims to provide Python bindings for WRY, a cross-platform webview library. WRY is a trademark of the Tauri Program within the Commons Conservancy and PyWry is not officially endorsed or supported by them. PyWry is an independent and community-driven effort that respects the original goals and values of Tauri and WRY. PyWry does not claim any ownership or affiliation with WRY or the Tauri Program.