generate_song.py

import decoder

from pathlib import Path
from typing import Optional
import argparse

from markovify import Chain

def main(model: Path, output: Optional[Path] = None):
    with open(model, "r") as file:
        chain = Chain.from_json(file.read())

    text = chain.walk()
    midi = decoder.decode(text)

    output = output or model.with_suffix(".mid")
    midi.save(output)

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Generate a Markov chain from a directory of MIDI files.")

    parser.add_argument(
        "model",
        help="The path to a '.json' model file, generated by generate_model.py.",
        type=Path
    )
    parser.add_argument(
        "--output", "-o",
        help="The path to the output file. Defaults to the same path as the input file, with a `.mid` file extension.",
        default=None,
        type=Path
    )

    main(**vars(parser.parse_args()))