apng

#!/usr/bin/env python3
"""
CLI tool for splitting and joining animated PNGS (APNG)
requires: pip install click apng
license: GPLv3+
author: bernardas.alisauskas@pm.me
"""
import click
from apng import PNG, APNG


@click.group()
def main():
    """split/join APNG files to PNG"""
    pass


@main.command('split')
@click.argument('file', type=click.File('rb'))
def cmd_split(file):
    """split APNG file into multiple PNG files"""
    filename = file.name
    im = APNG.from_bytes(file.read())
    for i, (png, control) in enumerate(im.frames):
        with open(filename.replace('.png', f"_{i}.png"), 'wb') as f:
            f.write(png.to_bytes())


@main.command('join')
@click.argument('filename')
@click.argument('files', type=click.File('rb'), nargs=-1)
def cmd_join(filename, files):
    """split APNG file into multiple PNG files"""
    im = APNG()
    for file in files:
        im.append(PNG.from_bytes(file.read()))
    im.save(filename)


if __name__ == "__main__":
    main()