Extract chapters part of the Youtube-dl's json info into a CUE file

ydljson2cue.py

#! python3
"""
Extract chapters part of the Youtube-dl's json info into a CUE file.

This file is in the public domain.

Requirements:
    pydantic
    python>=3.6

Steps:

1. Download JSON information (`--skip-download` skips downloading the video/audio): 
   `youtube-dl --skip-download --write-info-json YouTubeURL`
2. Generate CUE file: `ydljson2cue.py json_filename [optional video/audio extension]`
"""
from pathlib import Path
from pydantic import BaseModel
from typing import List, Union
import os


class Chapter(BaseModel):
    start_time: int
    end_time: int
    title: str


def to_cue_data(chapter: Chapter, idx: int) -> List[str]:
    return [
        f"    TRACK {idx:02d} AUDIO",
        f'        TITLE "{chapter.title}"',
        f"        INDEX 01 {chapter.start_time // 60}:{chapter.start_time % 60}:00",
    ]


class YoutubeDlInfoJson(BaseModel):
    chapters: List[Chapter]
    title: str

    class Config:
        ignore_extra = True


def convert(ydl_info: YoutubeDlInfoJson, output_file):
    cue_data = [
        f'TITLE "{ydl_info.title}"',
        f'FILE "{output_file}" WAVE',
    ]
    for idx, chapter in enumerate(ydl_info.chapters):
        cue_data.extend(to_cue_data(chapter, idx + 1))
    return cue_data


def read_and_write(input: Union[str, Path], ext="mp3"):
    input = Path(input)
    basename = os.path.splitext(input)[0]
    output = input.parent / f"{basename}.cue"
    ydl_info = YoutubeDlInfoJson.parse_file(input)
    cue_data = convert(ydl_info, input.parent / f"{basename}.{ext}")

    output.write_text(os.linesep.join(cue_data))


if __name__ == "__main__":
    import sys

    argv_len = len(sys.argv)
    if argv_len == 2:
        file = sys.argv[1]
        ext = "mp3"
    elif argv_len == 3:
        file, ext = sys.argv[1:]
    else:
        print("Usage: script_name json_filename [extension]", file=sys.stderr)
        sys.exit(1)
    read_and_write(file, ext)

I tried your script which runs properly but giving a warning with pydantic-2.5.3 which was installed by pip.
$ python3 ydljson2cue.py test.json ydljson2cue.py:59: PydanticDeprecatedSince20: The parse_filemethod is deprecated; load the data from file, then if your data is JSON usemodel_validate_json, otherwise model_validateinstead. Deprecated in Pydantic V2.0 to be removed in V3.0. See Pydantic V2 Migration Guide at https://errors.pydantic.dev/2.5/migration/ ydl_info = YoutubeDlInfoJson.parse_file(input)

@6b6561 Thanks. In response to Pydantic's change, maybe replace that piece of code by first load the file into dict with python's json library, and then convert it to YoutubeDlInfoJson with YoutubeDlInfoJson.model_validate.