!pip install pytube moviepy pydub
from pytube import YouTube
from moviepy.editor import AudioFileClip
import re

# ▼ URL補正（短縮URL対応 & ?si=削除）
def clean_url(url):
    if "youtu.be" in url:
        video_id = url.split("/")[-1].split("?")[0]
        return f"https://www.youtube.com/watch?v={video_id}"
    
    url = re.sub(r"&si=.*", "", url)
    url = re.sub(r"\?si=.*", "", url)
    return url


# ▼ MP4 ダウンロード
def download_mp4(url):
    yt = YouTube(url)
    stream = yt.streams.get_highest_resolution()
    stream.download(output_path=".", filename="video.mp4")
    print("MP4 保存完了：video.mp4")


# ▼ MP3 ダウンロード
def download_mp3(url):
    yt = YouTube(url)
    stream = yt.streams.filter(only_audio=True).first()
    audio_path = stream.download(filename="audio_temp.mp4")

    audio_clip = AudioFileClip(audio_path)
    audio_clip.write_audiofile("audio.mp3")
    audio_clip.close()

    print("MP3 保存完了：audio.mp3")


# ▼ メイン実行
url = input("YouTube URL を入力してください：")
url = clean_url(url)

download_mp4(url)
download_mp3(url)