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Likianta D
Likianta D

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Turn Any Python Function into a GUI

#python #ui #cli #programming

Turn Any Python Function into a GUI

What if you could get a GUI without writing GUI code?

The community already has two well-known answers: PyGUIAdapter and Gooey.

  • PyGUIAdapter

  • Gooey

And when a terminal UI is enough, Trogon is a library I personally like a lot.

Now there is a new challenger: ArgSense.

So what is different?

ArgSense is a command line argument parser at heart. The GUI is a recent, optional layer on top of it. The pitch:

  • Your function does not change. ArgSense reads its signature and annotations and builds the interface from them: every parameter becomes a widget.
  • It stays light. Compared with Gooey, the UI is a motorcycle next to a car: fewer knobs, much less to learn.
  • It can produce a desktop launcher. A double-clickable .exe or .lnk, with an icon of your own.
  • The launcher is tiny. A .lnk is 1–2 KB; an .exe is about 1.2 MB. It does not bundle a Python runtime — it starts the venv you already have. A PyInstaller or PySide build of the same script weighs tens or hundreds of megabytes.

  • It does not build on argparse. The parser is ArgSense's own, and that is the library's main business.

    Before (argparse + gooey):

    from gooey import Gooey, GooeyParser

@Gooey(program_name='Image Resizer')
def main():
    parser = GooeyParser(description='Resize images in a folder.')
    parser.add_argument(
        'src', metavar='Source folder', widget='DirChooser'
    )
    parser.add_argument(
        '--width', type=int, default=800, metavar='Target width'
    )
    parser.add_argument(
        '--overwrite',
        action='store_true',
        metavar='Overwrite originals',
    )
    args = parser.parse_args()
    print(args)

if __name__ == '__main__':
    main()

    After (argsense):

    from argsense import cli

def resize(src: str, width: int = 800, overwrite: bool = False):
    """
    Resize images in a folder.

    params:
        src: the folder of images.
        width: the target width in pixels.
        overwrite: replace the originals instead of writing copies.
    """
    print(f'resizing {src} to {width}px ...')

if __name__ == '__main__':
    # python main.py :gui
    cli.run(resize)

  • No PySide, PyQt or wxPython. The form is rendered by streamlit-canary, and the native window is opened by pyapp-window.

Install 

pip install argsense[all]
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That installs ArgSense plus what the GUI needs: pillow (to turn a PNG icon into an ICO), streamlit-canary (the form), pyapp-window (the window), and a few more.

One more thing, if you want the desktop launcher: two binaries are deliberately not shipped in the wheel.

python -m argsense pull-launcher-misc
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It fetches rcedit.exe (~1.3 MB) and stub.exe (~1.2 MB)1 from the repository's misc folder into <argsense>/launcher/assets/.

Use

One function 

# main.py
from argsense import cli


def resize(src: str, width: int = 800, overwrite: bool = False):
    """
    Resize images in a folder.

    params:
        src: the folder of images.
        width: the target width in pixels.
        overwrite: replace the originals instead of writing copies.
    """
    print(f'resizing {src} to {width}px (overwrite={overwrite})')


if __name__ == '__main__':
    cli.run(resize)
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First of all it is a command line tool:

python main.py --help
python main.py ./photos --width 1280
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Append :gui, and the same function becomes a window:

python main.py :gui     # a native window
python main.py :guiw    # a browser tab (w = windowless, like "pythonw")
python main.py ./photos --width 1280 :gui  # prefill args into components
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A desktop launcher 

python -m argsense create_launcher
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python -m argsense create_launcher main.py "Image Resizer" -a "./photos --width 1280"
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  • The output goes to the desktop by default: Image Resizer.exe when the toolchain is in place, otherwise Image Resizer.lnk. Pass -o <dir> to write it elsewhere; a shortcut is then left on the desktop.
  • -a bakes arguments into the launcher, so the form is prefilled on double-click.
  • -i logo.png sets the icon for both the launcher and the window (a PNG is converted to a multi-size ICO).
  • -t / -z set the window title and size; -p pins the port (the default is a free port, picked at every start).
  • -c keeps a console window around, for debugging.
  • A module works as well: create_launcher myapp.main -n MyApp is the equivalent of python -m myapp.main :gui.

One caveat: the launcher does not bundle a Python runtime. It records the interpreter of the venv you built it from, which makes it perfect for your own machine and useless on a machine without your environment.

Who is it for

  • Tools you build for yourself, where remembering a dozen flags is the annoying part.
  • Command line scripts with a lot of parameters.
  • Machines where you set the environment up but the person using it does not live in a terminal — hand them a desktop launcher instead.

Not for: polished desktop apps that need custom widgets and hand-made layouts. Those still belong to Qt, or to a web front end.

Try it 

pip install argsense[all]
python -m argsense pull-launcher-misc
python -m argsense welcome gui
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welcome also takes cli and tui, if you want to see the other two faces of the same demo.

If you have ever put off building an interface for a script, try :gui first — it costs one token.

  1. If GitHub is slow or blocked where you are, use the mirror: python -m argsense pull-launcher-misc --mirror-site. ↩

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